In his first interview since the Madoff scandal broke, Securities and Exchange Commission chairman Christopher Cox told the Washington Post he was not responsible for the agency's failure to detect the alleged fraud, based on the information he was given but acknowledged the case was 'troubling'.

'We've done everything we can during the last several years in the agency to make sure that people understand there's a strong market cop on the beat,' he said.

Asked whether he should be blamed for a culture of lax enforcement that allowed the Madoff fraud to go undetected, he said: 'Absolutely not. In fact, it's in the DNA here that people thrive on bringing big cases.'

However he called the Madoff case 'a big asterisk' in what he considers his agency's otherwise commendable record.

'The case is very troubling for that reason. It's what the SEC's good at. And it's inexplicable.'

Prosecutors say that former Wall Street baron Bernard Madoff has confessed to losing upwards of US$50 billion (S$72 billion) over years of running a pyramid scheme, where new investors were secretly fleeced to pay returns to earlier investors.

The 70-year-old Madoff, former chairman of the Nasdaq stock market and a mainstay of the powerful American Jewish community, is currently free on bail of US$10 million as police continue their probe.

Mr Cox meanwhile also rejected criticism that the agency's alleged laissez-faire approach to oversight contributed to the unravelling of global finance markets.

'What we have done in this current turmoil is stay calm, which has been our greatest contribution - not being impulsive, not changing the rules willy-nilly, but going through a very professional and orderly process that takes into account unintended consequences and gives ample notice to market participants,' Mr Cox said.

The agency's restraint 'has really been a signal achievement for the SEC,' the chairman added.

Critics have said that Mr Cox, 56, has been restrained to a fault, and accuse the agency of passivity during the worst financial crisis in decades.

Mr Cox said the biggest mistake of his tenure was agreeing in September to an extraordinary three-week ban on short selling of financial company stocks - a move he told The Post he reluctantly made under under intense pressure from Treasury Secretary Henry Paulson and Fed Reserve Bank Chairman Ben Bernanke.

They 'were of the view that if we did not act and act at that instant, these financial institutions could fail as a result and there would be nothing left to save.' Cox, a former Republican congressman from California, became SEC chairman in mid-2005. He plans to step down early next year, before his full five-year term expires.

President-elect Barack Obama has named Mary Schapiro, a former SEC commissioner, to replace him. -- AFP