David von Blohn / NurPhoto / Sipa USA Activists' posters in front of the German Chancellery in Berlin show solidarity with whistle-blower Edward Snowden as he seeks asylum in countries like Germany on July 4, 2013

Correction appended: July 11, 2013.

In the summer of 1985, KGB colonel Oleg Gordievsky was called back to Moscow from the Soviet embassy in London, where he was serving as a resident spy. As a pretext, his commanders told him that he was going to receive an award for his service. But in fact the KGB suspected him of being a double agent — which he was — and they were looking to interrogate him. So upon his arrival, his KGB colleagues, still concealing their suspicions, took him to a comfortable country estate in the suburbs of the Russian capital, much like the one where Gordievsky and other former spies believe Edward Snowden, the NSA whistle-blower, has spent the past few weeks.

Since June 23, Snowden has been marooned somewhere in Russia, far out of reach of the U.S. government, which wants to put him on trial for exposing the secrets of U.S. intelligence agencies. The official story coming from the Russian government since then is that Snowden has been holed up in the transit zone of Moscow’s Sheremetyevo airport, waiting for some third country to grant him asylum. But few experts or officials in Moscow still believe that to be true. The accepted wisdom, unofficially acknowledged by most Western and Russian sources, is that Snowden was taken soon after his arrival — if not immediately — to a secure location run by some arm of the Russian government.

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The reason has to do with the secret data Snowden stole from his former employers at American intelligence agencies. This data, which he can likely still access, would make him a high-value target for Russian spies. “Without a doubt, a person with inside knowledge like that, live and in the flesh, would be a very useful catch,” says Mikhail Lyubimov, a 20-year veteran of the KGB who headed the agency’s spying activities against the U.K. and Scandinavia in the 1970s. “He is carrying information of great importance.”

As an experienced hacker and computer expert, Snowden could, however, be expected to protect all his secrets through encryption and by storing them in a remote data cloud. Nikita Kislitsyn, the editor of Russia’s Hacker Magazine, says encryption systems are available that would likely stump the experts working for the Russian government. “We don’t know the exact capabilities of our special services,” he says. “But there are programs on the market today that encryption experts believe to be very solid. Their algorithms would take years to crack even with the kinds of supercomputers available to the state.”

In order to access Snowden’s data, Russian security services would therefore need him to provide the encryption keys and passwords to his data cloud, which he does not seem likely to give up voluntarily. His supporters have cast him as an altruistic whistle-blower; handing over secrets to the Russian government would seem to undermine the values of transparency that he extols.

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So Gordievsky believes Snowden would have gotten roughly the same treatment that the KGB spy got back in 1985. “They would have fed him something to loosen his tongue,” Gordievsky says by phone from the U.K., where he has been living in exile for nearly three decades. “Many different kinds of drugs are available, as I experienced for myself.” Having been called back to Moscow, Gordievsky says his KGB comrades drugged him with a substance that “turned out his lights” and made him “start talking in a very animated way.” Although the drug wiped out most of his memory of the incident, the parts he did recollect horrified him the following morning, when he woke up feeling ill. “I realized that I had completely compromised myself,” he says.

One of the substances the KGB used for such purposes at the time was called SP-117, which is odorless, tasteless and colorless, according Alexander Kouzminov, a former Russian intelligence operative who describes the drug’s effectiveness in his book, Biological Espionage. Now living in New Zealand, Kouzminov worked in the 1980s and early 1990s for the Foreign Intelligence Service, the spy agency known as the SVR, which handles undercover agents, or “illegals,” stationed in foreign countries. In his book, Kouzminov writes that various drugs were used periodically to test these operatives for signs of disloyalty or diversion. Once the drug had worn off, the agents would have no recollection of what they had said and, if their test results were satisfactory, they could be sent back into the field as though nothing had happened.

Although it is impossible to determine which of Russia’s secret services could be handling Snowden’s case, Gordievsky believes it would be either the SVR or one of the offshoots of the Federal Agency for Government Communication and Information, known as FAPSI. Before its functions were handed to two other agencies in 2003, FAPSI was the Russian analogue of the U.S. National Security Agency, where Snowden worked as a contractor before fleeing to Hong Kong in May with a cache of the agency’s files.

(MORE: Putin to Offer Snowden Asylum, but With a Catch)

Most of the secrets Snowden has exposed are related to the NSA’s vast surveillance programs, which he revealed to be collecting data on tens of millions of phone calls and Internet communications around the world. FAPSI’s functions are now split between two of Russia’s main security agencies—the Federal Security Service, or FSB, and the Federal Guard Service, or FSO. These agencies operate their own data-gathering stations in various countries, mostly in the former Soviet Union, and all of them would be keen to learn as much as possible about the work of their American counterparts. “[Snowden] could have information about the internal parameters of these systems, their lists of targets and priorities,” says Vladimir Rubanov, who headed the KGB’s analytical directorate in 1991–92, after which he served three years as deputy head of the Russian Security Council. “Yes, all of this is pretty interesting,” he says. “And it is a fool who has the chance to get information and misses it.”

But Rubanov, who has remained closer to the security services than the other former agents TIME interviewed, tried to downplay Snowden’s importance. “I don’t think he has anything that would really surprise us,” says Rubanov, who sits on the Council on Foreign and Defense Policy, a state-connected think tank. “The Americans shouldn’t worry so much,” he says. And even if Russia wanted to get Snowden’s encryption keys, there would be no need to drug him. “I think he would give them up himself. It’s just a question of price.”

Asked where Snowden might be taken to negotiate such a matter, Rubanov says each agency has numerous country estates, or dachas, around Moscow that could be used. The headquarters of the SVR, for instance, is in a suburb called Yasenevo, a short drive from Sheremetyevo airport, and it includes a swimming pool, basketball court and restaurant, all hidden behind a high wall that runs along the perimeter. (A slide show on the agency’s website shows some of its amenities.) “Even out of humanitarian considerations, why not take him to some kind of comfortable place, where he can have all of his technical needs provided for?” asks Rubanov. “For a foreign guest, all of that should be available.”

But a retired officer of the SVR, who holds the rank of major general, insists that Snowden is not being held at any of the agency’s facilities. “At this point, this story has nothing to do with the security services,” he says, asking not to be named. “It is purely political now.”

(MORE: Snowden and Putin: U.S. Whistle-Blower’s Fate Is in Russian President’s Hands)

Politically, Snowden seems to be a liability for President Vladimir Putin, who has said several times that he would prefer for Snowden to get on a plane out of Russia as soon as possible and stop disturbing Moscow’s already fraught relationship with Washington. Snowden’s most likely destination now seems to be Latin America, where several countries — namely Venezuela, Bolivia and Nicaragua — have agreed to grant his asylum. But getting him there may be a slow affair. Snowden’s U.S. passport was annulled in June, and it may take days or weeks for him to get new travel documents. That process, says Gordievsky, could be delayed if Russia feels it needs more time with the American. “They will not let him go without turning him inside out,” he says. “But by now I think they’ve gotten all they need from him. They’ve had plenty of time, which is why they’re letting him go so easily.”

Far more easily, it seems, than Gordievsky’s escape in 1985. Although the KGB’s reasoning remains a mystery to this day, the agency decided not to arrest Gordievsky immediately after he outed himself as a double agent who had passed secrets that year to the British intelligence service. Instead, the KGB put him under surveillance, which he managed to shake a few days later while on a walk around the neighborhood. His British handlers then smuggled him across the Finnish border in the trunk of a diplomat’s car. Wherever Snowden is at the moment, he’s likely hoping he makes it out of Russia at least as safely as Gordievsky did.

MORE: On the Run to Moscow, Edward Snowden Keeps Americans Guessing

The original version of this story mistakenly described the Federal Agency for Government Communication and Information (FAPSI) as Russia’s equivalent of the NSA. FAPSI’s functions were actually split between two other Russian federal agencies in 2003. The story has been amended to reflect this.