One of Klop’s post-war tasks was to keep an eye on Czechs in London. There had been a close relationship between British and Czech intelligence during the war and some of Klop’s best contacts, including Josef Bartik and Vaclav Slama, chose to return home in 1945-46 to the support the government of Edvard Beneš.

Beneš, who had led the Czech government in exile in London, returned as President in 1945, a position he held until 1948. He awarded Klop the Czechoslovak medal of merit, first class, and also gave a plethora of other awards, including the Order of the White Lion for Dick White, Guy Liddell and the directors of MI5 and MI6, Sir David Petrie and Sir Stewart Menzies.332

From 1947 Klop made a habit of spending Saturday afternoons with his old friends at the Czech Deuxieme Bureau office at 42 Wilton Crescent, Belgravia picking up the gossip on the exiles in Britain and the progress of the regime in Prague.

Czech refugees from the Nazi invasion had begun to arrive in Britain en masse in 1938-9 and been catered for by the Czech Refugee Trust, set up by Sir Walter Layton, chairman of the Liberal-leaning News Chronicle. It quickly became a matter of concern to MI5 that this organisation was being controlled from within by Communists, both British and exiles. They struggled to convince Sir Henry Bunbury, the retired civil servant responsible for administering the Trust, that Communists were taking on positions of responsibility within the organisation with the intention of controlling it. Klop was drawn into this controversy and began working closely with Vaclav Slama who warned that nearly 90 per cent of the refugees taken in by the Trust were socialists and Communists of German ethnic origin and therefore potential spies and infiltrators. He offered to draw up a list of the chief suspects. The director general of MI5, Sir Vernon Kell, warned the Home Office of this on at least two occasions and Klop’s boss Dick White lamented:

One known Communist whose name cropped up in this connection was an American architect, Hermann Field, who married an English Communist supporter, Kate Thorneycroft. MI5 noted that he had been in Poland in 1939 when Germany and the Soviet Union both invaded under the aegis of their joint non-aggression treaty. Field had shown outstanding qualities of leadership and personal courage in bringing hundreds of refugees to the West. But he was known to have spent part of the 1930s on a collective farm in Russia and was believed to have trained as a Comintern agent for the purpose of infiltrating Western society and promulgating the Soviet creed. He was a known associate of William Koenen, the German Communist responsible for the London branch of the Comintern. His brother Noel, who shared his political convictions, worked during the war for the League of Nations in Geneva. These two brothers, and the Czech Refugee Trust, would now feature prominently in Stalin’s Cold War purges of Eastern Europe.

As Poland, Hungary, Bulgaria and Romania fell increasingly under Soviet domination in the immediate post-war period, Czechoslovakia held out a glimmer of hope that an independent, reforming government, under President Beneš, might survive by negotiating a careful path between the might of the dominant power in Eastern Europe and the desire to benefit from the modernising influence of the Western Allies. Britain was anxious to see it succeed, feeling under some obligation for its abandonment of Czech interests at Munich in 1938 and the subsequent contribution that the government in exile in London and its armed forces had made to defeating Hitler. It was not to be. After elections in 1948, Communists increasingly controlled the main offices of state. Their influence, dictated by Stalin, led the country to reject American aid under the Marshall Plan. The Americans blamed the snub on the failure of President Beneš and his Foreign Minister Jan Masaryk to be sufficiently robust in their resistance to Stalin. Within weeks Masaryk died in a fall from a Foreign Ministry window; whether he committed suicide, fell accidentally, or was pushed, has never been finally established. But it marked the end of any pretence that Czechoslovakia was anything other than a Soviet satellite.334

Into this new regime in October 1948 stepped Noel Field, aged forty-four, British-born of an English mother and an American father. He was a committed Communist who had taken it into his head that his future lay in a career as a university lecturer in Prague. In his pursuit of this objective he would plunge his family into the nightmare world of secret police, incarceration without charge and treason trials where the verdict was inevitable and the death sentence a probability. The British-based Czech Refugee Trust would feature in the evidence as an alleged MI6 front operation.

Noel Field had worked as a senior economic adviser for the US State Department before taking a job in 1936 with the League of Nations in Geneva. When the Second World War broke out he stayed on in Switzerland as a member of the Unitarian Service Committee formed to offer relief to refugees from Nazi persecution. It was particularly active in Czechoslovakia where the Unitarian Church had many adherents. Noel Field was introduced to Allan Dulles, head of the Office of Strategic Studies in Berne, who realised that Field’s refugee contacts were potential sources for US intelligence. As the war progressed, Field was also able to supply Dulles with contacts, many of them Communist sympathisers, in occupied Germany. It was never entirely clear in whose interests Field was working, Moscow’s or Washington’s, and in post-war years Dulles came to believe he had been duped. Equally, the Communist regimes of Eastern Europe regarded the Unitarians as a CIA front.

When the new Communist government in Prague came to carry out security checks in connection with Noel Field’s application for a position at the Charles University, what they found was a man with many contacts, not only in Czechoslovakia but among members of the politburo throughout the Eastern Bloc; plus a highly suspicious association with Allan Dulles. As inquiries broadened, it became apparent that his younger brother Hermann had equally extensive contacts in Poland – pre-war he had been based in Katowice near the Czech border working for the Czech Refugee Trust.

In May 1949 Noel Field returned to Prague believing he was on the verge of getting his coveted university appointment. Instead, he simply disappeared. His German wife Herta, living in Geneva, chose not to mention this to the American authorities. In August she and Hermann went to Prague to look for him. They drew a blank and Hermann flew on to Warsaw … and vanished. Herta decided it was time to visit the US authorities in Prague. Twenty-four hours later she too had gone missing. The following year Erica Glaser Wallach, whom Noel and Herta Field treated as their daughter, also travelled behind the Iron Curtain in the hope of picking up the trail. She was neither seen nor heard of for many years.

Then the purges and the trials began. Klop’s wartime contact in London, Josef Bartik, who had been promoted to the rank of general and head of Czech military intelligence in 1945, had already lost his job on the strength of forged documents.

Noel Field had been handed over by Czech security to their Hungarian counterparts. In September 1949 the trial began in Budapest of the former Foreign Minister László Rajk and accomplices. They pleaded guilty to belonging to an organisation dedicated to the overthrow of the state. They had been recruited, it was alleged, by Allan Dulles, Noel Field and British intelligence agents in Switzerland. This was the first acknowledgement that Field was in Hungarian custody. Similar trials followed in Czechoslovakia and Poland. These Communist enemies within the state were often accused of being Titoists, supporters of the Yugoslav Communist leader who had broken away from Soviet constriction. Stalin was purging potential dissenters.

MI6 did not officially exist in those days and since none of the missing individuals was British it was not too difficult for the Foreign Office to adopt the policy that serves them well so often: they sat back and awaited developments. The Americans made the obligatory inquiries about their absent citizens but did not quite raise the hullabaloo that might have been expected.

After Stalin died, on 5 March 1953, the gulags slowly began to give up their secrets. The following December, Lt Col. Józef Światło, deputy head of internal security in Poland, defected and began to reveal how the terror trials had taken place and how the Fields, and their East European friends, had been set up by the security police, including Światło himself, to satiate Stalin’s lust for power and paranoia that he was being betrayed. He divulged some of the details on Radio Free Europe, the US-sponsored propaganda station whose broadcasts reached behind the Iron Curtain.

Extraordinarily, in October 1954 Hermann Field was freed from his Polish jail, given $40,000 compensation, and allowed to return to the US and his architects’ practice, taking his English wife with him. While Hermann was en route, Noel and Herta Field quietly emerged from their separate prisons, were reunited and astonished everyone by accepting the Hungarian authorities’ apologetic offer of a villa on the outskirts of Budapest where they could live out their lives in a Communist sanctuary of which they apparently approved. It took another twelve months for Erica Glaser Wallach to find her way out of a Russian labour camp but she too returned to the West. Between them they offered little by way of explanation but the impression lingered that they had been part of a CIA mission which had been exposed and for which retribution had been taken. Britain was in no position to criticise: this was the era of Philby, Burgess and Maclean when any number of agents behind the Iron Curtain had been betrayed.

Klop, with his keen interest in Czech intelligence matters, must have followed it with interest. He may even have been involved but there is very little information in the public domain to address that point. It was not until twelve years after his death that a different interpretation began to be put on these events. It was argued that the whole thing had been an elaborate CIA charade, implemented by Jozef Światło himself, on the instructions of Allan Dulles, who was by that time head of the CIA. Światło had been a double agent since 1948 when he had been recruited by MI6 and handed over to an American controller. The operation was codenamed Splinter Factor and its purpose was to win the Cold War by provoking antagonism between the nationalist sympathisers of the individual east European and the unflinching Soviet idealogues in their midst, laying the blame firmly at Stalin’s door. Dulles, it was said, set out to alienate every East European country from the Soviet dictator and bring about the collapse of the Soviet bloc from within.335

On 5 September 1945, Igor Gouzenko, aged twenty-six, a cipher clerk for the GRU – Soviet military intelligence – in Ottawa walked into the Canadian Ministry of Justice with more than a hundred secret documents stuffed inside his shirt. Shortly afterwards he walked out again, still with the wad of paperwork bulging under his jacket, and tried his luck at the Ottawa Journal. He was the first important defector of the immediate post-war era. Unfortunately, nobody believed him. He had burned his bridges with his employers and had nowhere safe to go. He hid out in a neighbour’s flat and it was not until the following evening, when Russian security men broke in and started ransacking his flat in search of the stolen secrets, that the Canadian authorities started to take notice. The documents soon revealed a network of agents stretching across the United States and Canada, linking back to Britain. The three countries had collaborated in the development of the atomic bomb, detonated over Hiroshima on 6 August. In particular, an agent Alek was quickly identified as Alan Nunn May, a Cambridge-educated physicist with long-standing association with the Communist Party who had been working on the heavy water reactor at Chalk River, Ontario. He had handed information on the project and samples of its key uranium isotopes U233 and U235 to his case officer, Pavel Angelov.

By 7 September news of the investigation began to filter back to Britain, straight into the hands of Kim Philby at MI6 who became the liaison point between Canada, MI6 and MI5, and the British government. Within a week Philby’s Soviet controller in London, Boris Krötenschield, was able to confirm to Moscow what they must already have guessed about the extent to which their Canadian network was compromised. However, Philby was able to buy them some time, first by subtly impeding the flow of information and then by leading the chorus recommending that there should be no arrests until Nunn May returned to Britain. MI5 was initially opposed to this and the Foreign Office feared that Nunn May would realise the game was up and flee to Moscow, but Philby’s view prevailed.

Among the stolen documents were the precise instructions from Moscow to the scientist laying down the procedure for establishing contact with his new Soviet handler in London. Since the documents could not be produced in court, catching the spy red-handed with a Soviet intelligence officer and possibly exposing a network in Britain was obviously an attractive option but it meant no action could be taken publicly against the ring in Canada. Philby and his masters had more time to wind up the operation and safeguard their best agents. With every day that passed Philby could tell them more about where the investigation was leading.

Nunn May was kept under observation on the plane from Canada and surveillance continued when he arrived at Prestwick at 6:15 a.m. on Monday 17 September and flew from there to Blackbushe airport in Surrey. MI5’s team of watchers were briefed to pick him up from there but they had a problem. He was not due to make contact with his new controller until 7 October at the earliest and round-the-clock surveillance over such a long period was impossible without being detected. His phone was tapped at King’s College, London, where he resumed his old job as a lecturer, and at his digs, which he kept changing. He took precautions to make sure he was not followed, including jumping on to buses at the last minute and watching from the conductor’s platform to see if anyone jumped on after him. He contacted hardly anyone, most days eating alone in restaurants near the college.

Nunn May’s instructions from Moscow, as revealed by Gouzenko, had been that he was to attempt a clandestine meeting with his new handler at 8 p.m. on 7 October or on any date ending in seven thereafter. It was to take place opposite the British Museum, in Great Russell Street, near the junction with Museum Street. Nunn May was to approach from the direction of Tottenham Court Road and have a copy of The Times tucked under his left arm. The contact would come from the direction of Southampton Row, clutching a copy of Picture Post in his left hand, and say to Nunn May: ‘What is the shortest way to The Strand?’ Nunn May would reply: ‘Well, come along. I am going that way.’ The contact would then say: ‘Best regards from Mikel.’

It was recognised from the start that there was a high risk that he would be tipped off somehow that the ring in Canada had been broken and his own position jeopardised. It was at this point that Klop was brought in.336 It was suggested that if Nunn May kept the rendezvous but his new handler failed to show, Klop should play the part of the Soviet handler, exchange signs and passwords with May and hope to persuade him to hand over secret documents which could then be used in evidence against him. If no documents materialised, Klop was then to warn Nunn May about what had happened in Canada and say that contact was being terminated. Nunn May would then be kept under close surveillance to see whether he tried to warn other traitors to lie low.337

When Guy Liddell first heard about it, talks were already going on at a high level and consequently, he complained, the whole thing was wrapped up in about four layers of cotton wool. He added: ‘Most people have not realised quite that an atomic bomb has been dropped in Japan and that the world now knows quite a lot about it.’338

One of the first steps the security services had taken was to deny Nunn May access to his own work notebooks, recently shipped back from Canada, or any other reports relating to atomic weapons. Now Liddell proposed a dramatic reversal of this policy. Nunn May should be fed a couple of secret but relatively innocuous papers in the hope that he would be tempted to hand them over to his new controller at the first rendezvous. Sir Wallace Akers, director of the Tube Alloys project, as Britain’s end of atomic research was known, was briefed to carry out the plan. Nunn May then confounded them by refusing to accept the papers on the grounds that he was not currently part of the research team and had no need of them.

As the date of the first rendezvous approached, Commander Len Burt of the Metropolitan Police Special Branch was brought in. He was on secondment to MI5 and, unlike their officers, he had powers of arrest. Burt was to watch over the rendezvous from the first floor of the Museum Tavern and use the pub telephone to call a telephone kiosk in Great Russell Street where one of the MI5 agents on the ground could take orders if they were to move in and grab either Nunn May, his contact, or both. Tommy Harris of MI5 was to drive around the museum area on the lookout for Russian secret service agents who might also be carrying out surveillance.

MI5 felt it had a number of options, none of them ideal: if the rendezvous took place and officers were sure secret papers had been exchanged they could arrest Nunn May and his contact; or they could let Nunn May walk away but remain under surveillance and arrest the Soviet agent once Nunn May was out of sight; or they could continue to keep both under surveillance pending a round of arrests at the Canadian end.

A decision had to be made at the highest level. Prime Minister Clement Attlee consulted the Canadian Prime Minister, Mackenzie King, and US President Harry Truman. Their first instruction, in mid-October, was that suspects in Canada and Britain should be discreetly interrogated without any publicity. MI5 felt constrained to point out the impossibility of such a policy. Recording it in his office diary, Guy Liddell indicated that serious consideration was being given to sharing the secret with the Russians in any case. He wrote:

So the decision was to do nothing. To watch and wait and keep Klop in reserve in case an opportunity arose to use him.

Meanwhile, Kim Philby continued to keep Moscow abreast of the investigation, reassuring them on 18 November 1945 that neither Nunn May nor his Soviet controller had turned up for four scheduled rendezvous fixed for 7, 17, 27 October and 7 November. He passed on MI5’s opinion that Nunn May had not put a foot wrong: no suspicious contacts; no signs of being afraid or worried; and carrying on with his academic research. They had come to the conclusion that Nunn May was a tough customer who would not crack unless confronted with convincing evidence.

Philby also revealed that the matter was now a political decision at the highest level and that this involved consideration not only of maintaining friendly diplomatic relations with the USSR, but also of the future control over atomic secrets.340

In the event the watchers kept a thankless vigil in Great Russell Street throughout October, November and December without result. When the network was finally wound up in January, Nunn May confessed to Burt remarkably quickly, apparently shaken by the police officer’s detailed knowledge of his rendezvous arrangements and passwords. It was only towards the end of his life that Nunn May actually admitted that he had been tipped off by the Russians that his cover was blown and all contact was severed. There had been no question of him keeping the rendezvous.

The Russians seem to have been aware of Klop’s activities. He appeared in an undated document in NKVD files in a list of British agents who were reporting on individuals at the Soviet embassy in London and other Communist organisations. The list mentioned a number of journalists, among them Lady Listowel, daughter of a diplomat of the Austro-Hungarian empire, who published a postwar anti-Communist news sheet, East Europe and Soviet Union. Another writer, codename ‘Brit’ and identified as a journalist named Morton, had supposedly been keeping the Soviets’ military attaché and intelligence rezident in London, Major General Ivan Sklyarov, under observation. Sklyarov and his assistant, Col. Simon Kremer, had been responsible for the recruitment of the atom bomb spy Klaus Fuchs, who was introduced to them by Jurgen Kuczynski. In MI5 files now available at the National Archives, agent Brit is frequently referred to as a source on Russian activities but his identity is not revealed. Klop is described in the NKVD list as a White Russian officer.341 Blunt had filed a full report on Klop during the war and Philby had plenty of opportunity to add to it. Klop for his part had warned Dick White in 1946 that Philby’s first wife, Litzi Friedmann, was a Communist and Soviet agent. At the time, they were getting divorced and maybe because of that the information was discounted.342

Nadia’s sister Olia had lived throughout the war in Berlin. She had divorced her first husband and married his cousin, Ernest Steiner, who was, like her, a Russian émigré. He worked for the German electronics giant Siemens. Somehow, Nadia managed to track them down in the British controlled zone of Germany and, with Peter’s help, arrange for them to come to Britain. Quite how she achieved this at a time when thousands of displaced persons and refugees across Europe were being refused entry she never explains. It seems she got no encouragement from Klop who was so angry about it he threatened to leave her. Nevertheless, he delivered the couple from London to Barrow Elm in October 1946, before returning to Switzerland. When he returned to find them still comfortably ensconced in his country home more rows ensued. Klop went back to Switzerland once more, returning in 1948 and this time his attitude to his sister-in-law and her husband completely changed. Nadia herself had been away in Italy, working on costumes and set design for Peter’s film Private Angelo about a reluctant soldier in the Italian army. She arrived to find Klop, Ernest and Olia working as a team looking after a couple of defectors who had been granted political asylum.343

It was an occasion for another of Klop’s tall tales. He maintained that he had somehow procured enough lobster to concoct a lobster bisque, complete with cognac, cream and cheese, and had decanted it into a jar, which was travel with him and his defectors on the train from London to Gloucestershire, securely contained in his father’s old top hat box. Unfortunately Klop then placed the hat box upside down in the luggage rack and halfway through the journey observed, with a mixture of amusement and horror, that the bisque was dripping steadily on to the unwitting defector’s Homburg hat.344

It has not been possible to identify the victim of this deluge with any certainty but the most high-profile case of that time was the Soviet scientific adviser on aircraft and jet propulsion Grigori Tokaev, who had been sent to Germany by Stalin to bring back scientists from the German rocket research programme, by kidnap if necessary. Instead he fled into the British zone with his wife Aza and young daughter Bella and sought sanctuary. He had to be kept in a safe house because it was assumed that the Russians would send an assassination squad to silence him.

Tokaev needed delicate handling. He had not wanted to come to Britain at all and was furious when he discovered that the Canadians with whom he had been in contact prior to his escape were going to hand him over. He objected to Britain’s part in the Potsdam agreement under which Russia, America and Britain agreed the division of Germany into different control zones and he believed that Britain was in the habit of handing back defectors.345

Tokaev was able to give his interrogators some useful information about the state of Russian aeronautical research and was considered a prime asset for propaganda purposes. But his over-the top denunciations of Stalin and the Soviet system, serialised in the Sunday Express, were considered by some to be counter-productive. He was then involved in an attempt to lure a second defector Colonel J. D. Tasoev from Germany. Tokaev had been taken to Germany secretly in an RAF officer’s personal plane to persuade Tasoev to join him in Britain. The SIS officer overseeing the operation took a unilateral decision to bring the new man back immediately on the return flight. Tasoev was put up in MI5’s safe flat in Rugby Mansions, Kensington, and promptly changed his mind and demanded to be taken home. News of the fiasco leaked out and questions were asked in Parliament.

MI5 was further alarmed when it discovered that one of Klop’s former surveillance subjects, the White Russian Anatole Baykolov, was in touch with Tokaev. Baykalov was the subject of considerable suspicion that he was a plant by Russian intelligence, despite the fact that he was reportedly receiving covert funds from the Americans, through the Marshall Aid scheme, to finance an anti-Soviet campaign group.

As a result of the Tokaev case, Dick White, who was by then head of counter-intelligence at MI5, prepared a report on all twenty Russians who had defected since 1927. Only one, Vasilyi Sharandak, had chosen to come to Britain. He was a low ranking translator and black marketer who fled from Hungary in July 1947. Like Tokaev, he told his interrogators that it was widely believed in Russia that Britain handed defectors back.

Although Dick White could not have known it at the time, this was probably the result of the botched defection of Constantin Volkov in Istanbul in the summer and autumn of 1945. Volkov was deputy head of Russian intelligence in Turkey and approached the British embassy offering what White described as ‘a sensational catalogue of information’ including a list of Soviet agents in Britain. The local representative of MI6 was dubious and referred the case back to London. During the inevitable delay Volkov and his wife were forcibly repatriated by the Russians and never seen again. It only emerged later that the delay had been largely the fault of Kim Philby, the case officer in London who would have known that he was likely to be exposed by Volkov’s revelations. White’s report was not declassified until February 2014.346