Frank Monte sells himself in much the same way he plans to sell his story. When the private eye advertised anonymously for a girlfriend a few years ago, he described himself as a "sophisticated" gentlemen who "drives a Ferrari", "smokes cigars" and is "famous in New York and Sydney".

Now Monte is attempting to sell the big one - his life story - with similar understatement. "Over the past 35 years I have been detained by authorities, thrown out of countries, asked to leave others," he writes in The Spying Game: My Extraordinary Life. "I have been shot at, bashed, and had my nose broken and teeth smashed more times then I care to remember. I've guarded rock stars and executives, hired an army and fought with it, and travelled in my own version of Heart of Darkness along the remote waterways of Irian Jaya.

"In the course of this, I became a millionaire with a fabulous art and antiques collection, many properties, a Rolls-Royce and a Ferrari, and a series of glamorous girlfriends and famous acquaintances."

There was the time when Monte served as a bodyguard and spy to Aristotle Onassis and Jackie O.

And what about the high life in New York, where Monte and his 20-something girlfriend would attend parties "with huge ice castles, naked male and female waiters with their bodies painted all over, French champagne cascading out of fountains, entire orchestras hired for the night, carpets of fresh rose blooms flown in from Europe". Frank Monte, the former Sydney copper-turned-soldier of fortune, has become, in his own words, "the world's most famous private investigator".

"You've got to understand that he's a bit crazy," says Bob Lee, a veteran PI in Sydney who has known Monte since the early 1970's. "It's a very ticklish proposition to talk about this bloke. But he's very good at what he does, he's made a few quid, he's very secretive and pretty dangerous... He can be full-on charm, you can see why the Yanks love him. If he likes you, he loves you. If he hates you, he shoots you."

"Most people think I'm a hit man," admits Monte casually as he fiddles with his gold cufflinks in a Sydney office. "That has been a problem for my kids and myself, and for meeting a new lady... people misunderstand what we do."

In person, Monte gives little away. His broad face is devoid of emotion as he speaks about his life between bites of a salad sandwich. "Usually you can't read my expression," he explains in his book. "I've trained myself to be blank."

But appearances can be deceiving. Despite his poker face, Monte has invested years of emotional and physical effort in the book. The result is a series of Indiana Jones-style adventures which, according to the publisher, "reads like the plot of a blockbuster thriller".

Yet Monte hates the publisher's description of the book, ghostwritten by former pub rocker and crime writer Dave Warner. He sees his life more as a Shakespearean tragedy than a boy's own adventure. "Unwise people will see it as a fantastic adventure story but I don't think its adventurous at all," he says. "I think it's a tragic life, I'm about to finish it and I haven't got anywhere near the happiness that I've wanted."

In between the fantastic tales of the swashbuckling PI, Monte emerges as a man whose never-ending quest for love, money and publicity over nearly 40 years is balanced only by a loathing for himself, his life and his profession. Not that it started out that way. As a young man in Sydney in the late '60s, Monte loved his work almost to death, quickly establishing a reputation as a dangerous maverick in the shady world of private investigators.