In the spring of 1961, shortly after a young David Cornwell had completed his induction into MI6, he learned some sensational news. George Blake, veteran of the British secret service, had confessed to being a double agent. In the course of a decade of treachery, Blake had betrayed dozens, perhaps hundreds, of intelligence officers.

Two years later, another glittering star of MI6, Kim Philby, was also unmasked as a Soviet agent. He gave a partial confession to his oldest friend, Nicholas Elliott (also a member of the intelligence services), who in turn passed on that confession to Cornwell, by then a successful novelist writing under the pseudonym John le Carré. Elliott’s account was, as le Carré points out, remarkably short on the outrage that might have been expected from a spy who’d been duped. ‘The reason,’ he says, ‘is very simple. Spies are not policemen, neither are they quite the moral realists they like to think they are. If your mission in life is to win over traitors to your cause, you can hardly complain when one of your own … turns out to have been obtained by someone else.’

The murky world of betrayal and human transgression lies at the heart of many of le Carré’s novels. Now, in The Pigeon Tunnel, he shines a beam on the real-life traitors, double agents and gangsters who have inspired the characters of his fictional worlds. He also provides a warts-and-all portrait of his father, a gambler and trickster extraordinaire (and friend of the Krays) whose financial conjuring cast a shadow over le Carré’s formative years. ‘Spying did not introduce me to secrecy,’ he writes. ‘Evasion and deception were the necessary weapons of my childhood.’

The Pigeon Tunnel is not an autobiography. Those readers seeking a narrative of le Carré’s life should turn to Adam Sisman’s acclaimed biography, published last year by Bloomsbury. Le Carré’s purpose is revealed in his subtitle, ‘Stories from My Life’. This is exactly what we get – anecdotes, witticisms and sparkling vignettes, along with an eclectic cast of double agents and rogues who became models for le Carré’s fictional characters.

Stylistically, it reminded me of Robert Bruce Lockhart’s Memoirs of a British Agent – salacious, witty and self-deprecating. And, in common with Lockhart, it occasionally needs to be taken with a dose of salt. Many of the stories in this book have been told before, and the observant reader will notice that they have changed in the retelling. That caveat aside, they are extremely entertaining. Le Carré’s account of spending New Year’s Eve carousing with the soft-bearded Yasser Arafat – ‘the beard is not bristle, it’s silky fluff. It smells of Johnson’s Baby Powder’ – is one of the more memorable tales. ‘He has taken hold of the tail end of his keffiyeh,’ writes le Carré, ‘and is whirling it like Alec Guinness playing Fagin in the movie of Oliver Twist.’ Le Carré grabs Arafat’s waist, others grab his, and the entire entourage finds itself doing a crocodile dance through the Palestinian orphanage they are visiting, to the bemusement of the orphans who live there.

The Pigeon Tunnel is filled with such sketches. There’s a humorous anecdote of a lunch with Rupert Murdoch (who arrives at the Savoy with an ‘unsettling collection of rings on his left hand’). Margaret Thatcher gets a cameo role, while a whisky-toting Richard Burton takes centre stage in a chapter on the making of The Spy Who Came in from the Cold. But the most insightful stories are those that describe le Carré’s research trips. While gathering material for Our Kind of Traitor, he travels to chaotic, corrupt Moscow in order ‘to get a taste of the new order’. He’s soon consorting with some of the most unsavoury byproducts of glasnost, such men as Mr Dima, a dodgy, club-owning mafioso with ‘a bulbous, clean-shaven face, frozen in a half-sneer’. These characters eventually find their way into three of le Carré’s post-Soviet novels: Our Game, Single & Single and Our Kind of Traitor.

Research for another novel, The Mission Song, involves a grimly memorable trip to eastern Congo (against Foreign Office advice) in order to meet real-life warlords. Le Carré has already sketched out the fledgling characters in his head. But when he arrives in the country, he realises that they are ‘not real characters at all: just identikit men, cobbled together from hearsay’. His first genuine warlord is quite different from those imagined ones: ‘tall and suave and wears a well-cut blue suit. He receives us with consummate diplomatic ease … No warlord of my uninformed imaginings was ever like this.’

It is le Carré’s hankering for gritty realism that makes his novels so believable. And it is his evocative character sketches that make this book so entertaining. The real characters he conjures up here are no less entertaining than his fictional ones, perhaps because they, too, are overlaid with fiction.