Frank Monte is either an utter scallywag — the most likely scenario — or one of the smartest spies the world has ever seen.  A human headline since the 1990s, the jet-setting Sydney-based private investigator continues to provide entertaining copy ever since he popped up in Paul Toohey’s Rocky Goes West on the trail of a missing American heir in the wilds of PNG.

The latest chapter in the Monte saga concerns his failed relationship with Sharon Sargeant, whom, as The Daily Telegraph details, the detective dumped as his girlfriend after “finding out” that the well-known and irrepressible Sydney party girl runs an escort agency.

Most people would assume that an international private investigator to the rich and secretive is an occupation requiring the utmost discretion.  But Monte, one of the more colourful characters in Sydney’s gaudy menagerie of celebrity rogues, can’t seem to stay out of the news and, you might think, for all the wrong reasons.  Could his reputation as a dubious detective be a clever disguise, or is he really the disreputable fantasist that he appears to be?

Monte, once branded a liar by a judge in NSW over false claims, backed up with faxes found to have been forged, that he made concerning the 1997 murder of Gianni Versace, is the author of the self-published memoir The Spying Game: My Extraordinary Life as a Private Investigator, which he promotes with Barnumesque brass cheek as “the most famous and legally important book of the last 50 years”.

The book was originally going to be published in 2001 by Pan Macmillan, which pulped a reported 25,000 copies after the family of Versace objected to Monte’s claims that the late fashion designer had been murdered at his home in Miami by the Calabrian mob over a dispute involving proceeds from money laundering rather than simply being the victim of serial killer Andrew Cunanan.

Versace’s sister, Donatella, his brother, Santo, and the Versace company combined to sue Monte for defamation.  Interestingly, the Versaces did not go after Pan Macmillan, nor did they sue The Weekend Australian, which had published a lengthy profile of Monte airing the false Versace allegations, even though the potential recovery in monetary terms could presumably have been much higher.  Monte alone was their target and they eventually succeeded in bankrupting him after he failed to pay the $400,000 in legal costs awarded against him.

But if there really is no such thing as bad publicity then Monte may have emerged triumphant.  In any case it was not the first time, by his account, that Monte had encountered the sinister world of international crime.  Indeed Monte has told the story of how he became an upmarket PI through a kind of hoax that involved him taking credit for a murder he did not commit.

In the late 1960s, still in his 20s and disenchanted with the career he had begun as a member of the NSW police force, Monte claimed to have accepted a large sum to fly to New York and kill a wealthy American banker.  Monte says he took the money even though he had no intention of killing the man.  While in New York pondering his next move, the banker’s wife was killed in a freak car accident.  Monte claimed he took the credit for causing the death and in that way established himself as a man with the will and the means to take care of things.

Monte has gone on to claim that he became the confident of the late Aristotle Onassis after the mega-rich shipping tycoon sidled up to him in Milan one day wanting Monte to bug conversations of business rivals.  Monte also says he was hired by the immensely wealthy Rockefeller family in the 1990s to investigate the disappearance and presumed drowning of Michael Rockefeller over three decades previously in the remote jungle of Papua New Guinea while the young scion was on an expedition to film a documentary there.

Toohey writes that Monte’s interest in the case mainly consisted of his attempts to sell a film script he had written about the Rockefeller disappearance to Hollywood.  Toohey comments: “Some of what Frank says contradicts — actually, it punches in the face — much of what is accepted about Rockefeller”.  Monte, many would say, has made a career out of doing this.

Monte would have us believe that the outer Inspector Clouseau is craftily projected in order to distract us from the inner Sam Spade.  He once told an interviewer that “While to the outsider I might be partying and trying to attract the press, in reality I’m securing my next case”.  Though always upbeat, even defiant, in the face of the world’s disdain, in The Spying Game Monte writes that he sees his life as more Shakespeare than Boy’s Own.

“Unwise people will see it as a fantastic adventure but I don’t think it’s adventurous at all,” he writes.  “I think it is a tragic life, I’m about to finish it and I haven’t got anywhere near the happiness I’ve wanted.”

Monte, who has complained that he is a victim of the tall-poppy syndrome, has borne this melancholic burden with remarkable fortitude, and no doubt the most recent chapter in the saga of this self-styled international man of mystery will not be the last that is enacted in a blaze of publicity.

Simon Caterson’s Hoax Nation: Australian Fakes and Frauds, From Plato to Norma Khouri is published by Arcade.