The police now had a record of Litvinenko's previous meetings with the two men from Moscow, and it was a surprisingly long one. For the Itsu lunch on 16 October they were able to pinpoint the exact table where Sasha had sat with Lugovoy and Kovtun. Next they asked Scaramella to point out the table where he had met Litvinenko on 1 November. And then they compared the findings of the forensic teams that had combed the premises. All the evidence was that the radiation traces were not at the Scaramella table, but at the one where Sasha had met the two Russians. It was a major breakthrough, and the first suggestion that Litvinenko may have been attacked not just once but at least twice.
The police already knew that Lugovoy and Kovtun were contaminated when they flew into London for the 16 October meeting -their rooms at the Parkes Hotel were evidence of that - indicating that they brought the first consignment of polonium with them on that trip. If they had brought the poison into London, was it not likely they were intending to use it? Could they have tried to poison Litvinenko at that meeting? Or could they have merely been making a dummy run, a rehearsal for the real thing?
Oleg Gordievsky believes it was the latter. ‘This was a general rehearsal. Everyone involved in operations - secret services, military officers - performs general repetitions of their operations. This day was a rehearsal. They had poison with them because all warfare substances are meant to be at hand. They arrived, they made up nonsense, but they didn't decide themselves to use the ampoule.’
But when I asked Boris Berezovsky what he knew about the events of 16 October, his reply was startling. ‘As I understand it, they had a meeting with Alexander on 16 October in this sushi bar. And what I know is that Alexander felt bad for the first time after this meeting. I think that the dose of polonium that they used on that occasion was not enough to kill him… and that's the reason why they made the second attempt on 1 November.’
Berezovsky seems in little doubt that 16 October was a genuine assassination attempt. If a polonium vial was opened that day, it would explain why traces of radiation were still clearly evident on the table and chairs when forensic investigators swept them at the end of November, six weeks later. But it still would not explain the troublingly high level of Scaramella's own contamination. The police were perplexed; it was the one anomaly stymying the whole investigation. Then, on 30 November, the jigsaw gained its final piece: further medical examinations had revealed that Scaramella was not contaminated at all! The boffins at the Atomic Weapons Establishment in Aldermaston had got it wrong. Nick Priest thinks he knows why and it is not surprising: ‘It is clear that mistakes were made early on. Polonium is not a current analysis technique and there was cross-contamination of samples in the lab. Litvinenko had millions of becquerels in his urine [his urine was there too].’
With the riddle of Scaramella and the sushi bar seemingly solved, it was looking ever more likely that the poisoning had taken place exactly where the radiation trail suggested: in the Pine Bar on the afternoon of 1 November. Scaramella was little more than an innocent bystander who had been in the wrong place at the wrong time, as he himself had claimed all along. But if not Scaramella, what of Lugovoy and Kovtun?
By the time the police completed their investigations, they were long gone. Back in Moscow they were protesting their innocence, with Lugovoy saying, ‘I have the feeling someone is trying to set me up as the fall guy in all this.’ To bolster their case they were both admitted very publicly to hospital, apparently suffering from radiation poisoning. Kovtun was photographed with no hair and his lawyer announced he was critically ill or even in a coma. The Russian authorities let it be known that they believed the two men were also victims of an assassination attempt and that the Prosecutor General's Office would be opening an investigation into ‘the murder of Alexander Litvinenko and the attempted murder of Dmitry Kovtun’.
In London Peter Clarke's team was uncovering yet more evidence linking Kovtun and Lugovoy to the polonium trail. Radiation was found at the offices of Erinys and Titon International, the two security firms the men had visited with Sasha before he was poisoned. A spokesman for Titon confirmed that it had employed Litvinenko as a paid consultant and that he in turn had brought two Russian security consultants to visit them. Traces of polonium 210 had been found in their offices and the premises had been closed by the police pending further investigations. Finally, radiation was identified at the Pescatori restaurant north of Piccadilly, where Lugovoy is said to have dined on 1 November before meeting Litvinenko.
By early December Scotland Yard were certain that to solve the Litvinenko case they would need to speak to Andrei Lugovoy and Dmitry Kovtun. A flurry of correspondence with the Russian Prosecutor General's Office resulted in permission being received for nine detectives to fly to Moscow and they duly arrived on 4 December.