Once a million-selling man about town, he has cultivated obscurity for many years. But that may be set to change as his books are readied for republication

If Adam Diment hadn’t existed, someone would have had to invent him. In fact, someone did, several times. Depending on your cultural touchstones, you might find a hint of Diment in Austin Powers, or perhaps Peter Wyngarde’s turn as crime-novelist-turned-secret-agent Jason King from Department S.

But Diment isn’t a spy or secret agent, though his life is suitably enigmatic. He was an author of espionage thrillers, and a publishing industry dream made flesh: good-looking, hip, edgy and young – only 23 when he scored a six-book deal with Michael Joseph. His first manuscript The Runes of Death was published as The Dolly, Dolly Spy in 1967. Within a year, it had sold 1m copies and been translated into 13 languages.

Literary Austin Powers … the 1967 cover of The Dolly Dolly Spy. Photograph: PR

The few existing photographs of Diment look like stills from a movie, perhaps an alternative version of Antonioni’s Blow-Up. In one, smiling broadly beneath his blond mop-top, he is grooving down the King’s Road flanked by a pair of miniskirted women; another sees him apparently naked, rolling on a bed with model Suzie Mandrake, a long kif pipe in her hand.

Not unlike his creator, Diment’s hero Philip McAlpine was a less uptight Bond, a morally ambiguous spy who was no stranger to drugs and who embraced the permissive society with rather greater abandon than 007. Bond creator Ian Fleming had died a couple of years earlier, and the book trade was keen to capitalise on the spy market as the Bond movies took off. Diment was so perfect he could have written the role himself. Consider this from the opening chapter of The Dolly, Dolly Spy:

I have a 15-year lease on a three-roomed bit of real estate in Hampstead. A number of modish knick-knacks like expensive record players, deep foam, leather hide, swivel, wing-backed chairs, a wall-to-wall white Chinese carpet, floor-to-ceiling bookcase and a small but very good wine stock. My bedmate of the moment, more, inevitably, of her later, is called Veronica. Veronica Lom.

The Philip McAlpine books are certainly “of their time”, with all the baggage that implies. Men were men, drugs were hard and women were to be bedded. That said, Diment bought a new modish charm to a genre previously dominated by the comparatively stiff Bond. During their time, McAlpine was beyond cool: the Daily Mirror proclaimed him to be “the most modern hero in years … he likes birds, and sometimes marijuana”, while Publishers Weekly praised Diment’s debut as “a kinky, cool mod flare that is outrageously entertaining … If you appreciate clever plotting, plenty of excitement, sex at its most uninhibited, a dollop or two of explicit sadism, Adam Diment is a name to remember.”

But curiously, for an author whose books were advertised on the sides of London buses, Diment became a name to forget. The Dolly, Dolly Spy was followed by three more books – The Great Spy Race and The Bang Bang Birds, in 1968, and then Think, Inc, in 1971 – then the writer dropped mysteriously out of sight.

For an author who had courted publicity like he did, his disappearance was a mystery suited to one of his own novels. In 1975, the Observer published an article under the headline: “Whatever Happened to Adam Diment?” – but there were no answers, only rumour. He was living in Zurich, according to one story, editing textbooks on psychology. An American backpacker reported spending time with him in a guest house in Nepal, where the author would smoke local weed and bash out stories on a portable typewriter. Others told a rather more prosaic story, placing him hiding in plain sight in Kent.

Facebook Twitter Pinterest ‘He got bored with being well known’ … Adam Diment in 1967. Photograph: ANL/REX/Shutterstock

In 2008, the National Archive released two letters from 1969 addressed to the Bank of England and referencing an “FA Diment” – Diment’s first name is Frederick – fuelling a flurry of stories around currency swindling and European drug deals. But still there was nothing definite. Was there some explanation hidden in the letters as to why Diment went underground? Or was he, like Jason King, using novel-writing as a front while he worked as a spy himself?

As is the way of things, Diment was gradually forgotten, save for the very occasional ‘Where are they now? feature. Rather like this one, but with one crucial difference: Adam Diment is back.

Well, after a fashion. His books, so long out of print, are on the horizon again, thanks to the crowdfunding publisher Unbound. It plans to repackage the Philip McAlpine novels, if there is sufficient interest – and financial support – from readers.

Unbound’s Charlie Mounter remains suitably mysterious about how she contacted Diment, who is now in his early 70s. “He just didn’t like fame, and got bored with being well known, and never wants to be in anything remotely like that situation again,” Mounter says. “It’s no secret that he spends half his time travelling and half at home in Kent. He might be living under a different name, though. I can’t reveal how I contacted him.”

Diment seems a dichotomy: a superstar writer of the 60s who hated fame. So why, 50 years since The Dolly, Dolly Spy came out, is he happy for his novels to return? A wink and a nose tap from Mounter: “I can’t reveal how I managed to persuade Adam to let me publish his novels, but I’m very glad he has. Who knows, maybe Adam will enjoy his renaissance so much that he’ll indulge us with more of the good stuff?”

Perhaps half a century after his first flush of celebrity, he is ready for a return. As every spy aficionado knows, you only live twice…