Now the exploits of a Scottish-based former MI6 spy who risked jail by writing his memoirs are to be made into a television drama series.
Nicholas Anderson – not his real name – claims to have spent 19 years as a covert agent for the British Secret Intelligence Service, covering three periods of active duty in countries including Russia, Northern Ireland, Iraq, Afghanistan and Sudan.
But although an attempt to publish a factual account have been officially blocked, a fictionalised version is to be turned into a TV series.
Mr Anderson, now 59 and living in Edinburgh – his mother is Scottish – says he was recruited to the SIS from the Royal Navy in 1973, valued for his capacity for maintaining calm under pressure, ability to "think outside the box" and adopt the mindset of opponents.
First published last year, his book, NOC, Non Official Cover, is a fictionalised account of his experiences at the start of the 1990s.
It traces Mr Anderson's journey from Northern Ireland in the early 1990s, attending the funeral of a former SIS colleague, through the post-Communist USSR, accompanying a former Soviet scientist to the Democratic Republic of the Congo.
In one passage, Mr Anderson describes being ambushed and drugged in a Bulgarian hotel and taken to a prison cell, where he was tortured before being released without explanation.
He also recounts face-to-face encounters with IRA members during the Troubles, escaping mercenaries in the Congo charged with ensuring he did not return to the UK and his experiences as a hostage negotiator in central America.
He still bears the marks of apparent espionage trickery – he is missing two molars where he says satellite tracking devices and other gadgets would be implanted before operations – but he dismisses Hollywood depictions of covert agents.
"When you watch a spy film – I can't watch them for too long, because they have these Steven Seagals, Vin Diesel or Arnold Schwarzenegger, that can take out 15, 20 people – it's stupid.
"The law of the game is, if you're confronted with three people, you can't beat them. You just have to figure out how to get away. Two, you might be able to win; one, definitely. But you have to use your brain."
Production of a pilot programme is scheduled to start in January as a precursor to a 22-part series in locations such as Hungary and Morocco.