When two world leaders meet—in front of the cameras at least—it’s all smiles and handshakes. Behind the scenes, however, the intelligence agencies of each nation are constantly trying to learn as much as possible about the other nation, covertly or otherwise. And when it comes to getting that information advantage, there are few boundaries; spies will do whatever it takes to find out what the other party is thinking.
The same was true during the heyday of communism—even among Communist leaders. During the 1940s and 1950s, Soviet leader Joseph Stalin and Chinese chairman Mao Zedong had a solid relationship, but trust can only go so far. While both were leaders of Communist nations during the height of the Cold War, they were cautious about one another—to a degree, they were even competing against each other to become the de facto leader of the broader Communist movement. The two met face-to-face a number of times during the era, including in the winter of 1949, when Mao made a state visit to Russia.
Stalin wanted to learn more about his Chinese counterpart—and not just by talking to Mao. Despite their positive relationship, Stalin apparently decided that a bit of spying was in order. So according to former Soviet operative Igor Atamanenko, he made an investment in some new plumbing.
Spy methods were less sophisticated back then—technology didn’t allow for tiny cameras or listening devices. But one thing that the advancements of those days could do was analyze stool. Doctors often (and still do) used stool samples to help detect diseases and other health concerns; Stalin wondered if the same technique could be used to build a more in-depth personal profile of his intelligence targets. As Atamanenko told the BBC, “If [Soviet scientists] detected high levels of amino acid Tryptophan, they concluded that person was calm and approachable,” but “a lack of potassium in poo was seen as a sign of a nervous disposition and someone with insomnia.”
Whether those conclusions are scientifically proven is another matter: It was good enough for Stalin. According to The Telegraph, “special lavatories were installed for Mao’s ten-day visit in order for the Chinese leader’s stool to be collected in secret boxes instead of the sewers.” At least, that’s the former spy’s story; the modern Russian government neither confirms nor denies these events.