Soviet-era ruse that tricked 'escapees' into think they had fled Czechoslovakia

Running from 1948 to 1951, top secret "Operation Stone" created a number of false border posts near the Czech-German with an elaboration and attention to detail worthy of a film set in order to trick people into thinking they had made it to safety.

Once comfortable in what they thought was Germany a Czech secret policeman posing as an American intelligence officer would then ask them to write down all their contacts back home.

"It was human tragedy. These people were brought into areas which they thought were in the West," said Pavel Bret, from the Czech Republic's Centre for the Documentation and Investigation of Communist Crimes. "There were American flags, American uniforms, and they were also asked to give the names of people co-operating with Western intelligence. They still feel ashamed that they were tricked.

"But you cannot deny just how clever the operation was."

In one case an "American" officer even went as far as to share whisky with an escapee in order to make him feel more relaxed before he unwittingly betrayed his friends. Once the police had the information from the escapees, they were arrested and their friends rounded up, with many receiving harsh sentences from Stalinist judges.

Igor Lukas, a Czech-American historian who has researched Operation Stone, says that at least two of its organisers are still alive "and living in luxury".

"I think that 23 years after the fall of communism the state should be capable of bringing them to justice," he told the Czech newspaper Mlada Fronta Dnes. "Although it all happened decades ago the people who were duped still carry the consequences: both mental and physical."

Investigators said that although the operation was classified top secret by the communist government some 10,000 pages of documents have survived.