The man who blew the whistle on Madoff

Harry Markopolos, the man who tried for years to blow the whistle on mega-fraudster Bernie Madoff, has published a book about his 10-year crusade to unmask the financier's Ponzi scheme. The appropriately-titled No one would Listen tells how Markopolos first surmised the incredible truth - that the well-known and respected Madoff had been carrying out the biggest fraud of all time for decades - as far back as 1999.

Markopolos (pictured testifying against Madoff in 2009) is an almost-comic figure: a voluble, self-confessed maths nerd who for many years, while he struggled to have Madoff denounced, looked under his car every morning in case it was booby-trapped and carried a Smith & Wesson revolver.

He was deadly serious about the threat to his life, however, recently telling the Guardian: "Think about it. Here was a man that wiped out thousands of families. If he didn't have a reason to kill me, think about the feeder funds... They're all going to be ruined financially... What will people do to protect their lifestyles?"

The 'feeder funds' were companies who channelled individuals' savings into Madoff's bogus scheme. Markopolos accuses them of turning a blind eye to Madoff's activities.

Markopolos was a 'quantitative financial specialist' for a Boston firm when, in the late 1990s, he was asked to work out a way to produce the same spectacular – and remarkably consistent - returns as Madoff. It took him only a few months to come to the utterly logical deduction that Madoff's results seemed impossible because they were impossible.

"The math was so compelling," he told the Guardian. Markopolos worked out that Madoff's claims for his methods suggested he used more share options than actually existed on the Chicago exchange.

"If there's only $1bn of options in existence and he's many times that size, unless you could change the laws of mathematics, I knew I had to be right," Markopolos says. "And the risk-return ratios had never been seen in human recorded history. They were off the charts."

Markopolos approached the financial regulatory body, the Securities and Exchange Comission (SEC), in 2001 with his evidence. He persuaded journalists to write sceptical stories about Madoff and lobbied politicians. But it was not until December 11, 2008, that Madoff was finally arrested. So, why did nobody listen?

"It was just too big," says Markopolos. It seems the truth was so incredible nobody would even listen to his doubts. As he told the Guardian, "I'm coming in saying there's a hedge fund you've never heard of that's six to 10 times larger than anything you know that exists and by the way, it's corrupt, it's secretive and it's run by someone you already know, Bernie Madoff."

Another factor may have been Markoplos's personality. While some in the US have hailed him a hero, he has also been painted as an obsessive and a self-publicist. Last month, John Coffee, securities law professor at Columbia Law School told the Wall Street Journal Markopolos was "an emotionally unstable idiot savant", adding: "He was right but that does not mean he will be right again."

It's easy to imagine that it takes a particular personality type to swim quite so doggedly against the prevailing current for so long: one that is perhaps unconcerned by social pressure, and particularly certain of its rectitude. Markopolos himself says: "If you're a whistleblower, you need to be eccentric. You have to have a firm belief in your core values and you have to be willing to risk it all to do what's right."

But Markopolos has earned many fans: it has been proposed he should become the new head of the SEC, the organisation which resisted his approaches for so long. The Wall Street Journal, which sat on a dossier about Madoff provide by Markopolos for two years without using it, recently dismissed this idea with more than a trace of hauteur: "This is a crazy idea for a lot of reasons." So much for the ancien regime; on Facebook Markopolos enjoys the devotions of the Harry Markopolos Church, a 'religious' movement celebrating his achievements. ·