Instead of focusing solely on the issues of cancelling developing countries' debt and affording them financial support, Dr Wolfowitz will also face some awkward questions about his private life. How was it that Shaha Ali Riza, his Libyan-born, British divorcee girlfriend enjoyed a meteoric rise from communications officer in one of the bank's offices in the Middle East to a lucrative secondment to the US State Department where she earned more even than Condoleezza Rice, the secretary of state?

'It's ironic that Mr Wolfowitz lectures developing countries about good governance and fighting corruption while winking at an irregular promotion and overly generous pay increases to a partner,' said Bea Edwards, international director of the Washington-based Government Accountability Project.

Like other members of the Bush inner circle, Dr Wolfowitz enjoys unstinting loyalty from the US president and is unlikely to be forced out by the growing controversy, analysts say, despite calls for his resignation. His original appointment to the bank's top job was seen as a reward for his own long-time loyalty to the administration as well as an opportunity for the White House to exercise influence over policy in the developing world.

Yet his apology on Thursday for 'a mistake' he made in the handling of Ms Riza's promotion and pay rise cut little ice with the bank's infuriated workers. And according to those who have studied his career since 1972, when he became an adviser to Richard Nixon, the first of the six US presidents he has worked for, this controversy has clearly damaged his reputation.

'I don't suspect this will bring him down, but it is scandalous,' said Emira Woods, co-director of the left-leaning Institute of Foreign Policy Studies.

'He presents himself as the new era of Bush policy with principles and values, but his credibility is called into question. Wolfowitz is going around lecturing African leaders on corruption and telling them to be financially responsible and commit to anti-corruption measures when we know quite well that he has looked the other way.'

Ms Woods, who has met Dr Wolfowitz on several occasions, says he has been in government service so long that his personal life has become intertwined with his work on Capitol Hill.

'It's difficult to extract the person from the policies,' she says of a man said to enjoy working 18-hour days and who has played a variety of roles under several US administrations, including director of policy planning at the State Department, assistant secretary for East Asian and Pacific affairs, US ambassador to Indonesia and a hawkish deputy secretary of defence.

Though he has served under Nixon, Jimmy Carter, Ronald Reagan, George H.W. Bush and Bill Clinton, he is indelibly linked with the current US president, to whose mast he nailed his colours early on. Before the 2000 presidential election he was a founder member of Mr Bush's foreign policy advisory team known as the Vulcans. The team included fellow Bush loyalists Dr Rice, Richard Perle and Richard Armitage, who all went on to high office in the administration.

Dr Wolfowitz, a right-winger who had long advocated a first-strike policy to eliminate terrorist threats, was the driving force behind the decision in the wake of the September 11, 2001, attacks on the United States to invade Iraq and remove Saddam Hussein from power. 'You can't wait until you have evidence beyond a reasonable doubt that somebody did something in the past. You know that people are planning to do something against you in the future,' he told the San Francisco Chronicle in a 2002 interview.

Four months after the 2003 invasion he defended the decision to go to war, even as it became clear Hussein did not have the weapons of mass destruction that the White House had claimed. 'Intelligence about terrorism is inherently murky, and the US must be prepared to act on less than perfect information,' he said.

Born in New York to a Jewish couple whose parents left Poland in the 1920s, the young Wolfowitz was an idealist, and developed strong pro-Israeli sentiments during a year living in the country when he was 14 years old.

He cut his political teeth at New York's Cornell University, where he was an influential member of the secretive Quill and Dagger society for outstanding leaders, and went on to study politics at the University of Chicago.

It was there in 1969 that he and Mr Perle became involved in a pro-nuclear-arms lobbying group called the Committee to Maintain a Prudent Defence Policy after an introduction from his professor and mentor Albert Wohlstetter, which opened the door to Washington via an advisory job in the office of Republican senator Henry Jackson, a fervent anti-communist in the cold war era. From 1970 to 1973, Dr Wolfowitz lectured in politics at Yale University.

Yet despite his reputation as one of the more extreme of Mr Bush's close confidants - a velociraptor rather than a hawk, according to one former colleague - Dr Wolfowitz, 63, has a softer side, according to those who know him well. Since taking over the World Bank presidency he has visited more than 50 countries and takes time to meet, and take an interest in, the people of those nations.

'He is often depicted in the media as a neoconservative zealot, but on the road he is unfailingly polite, demonstrating a scholarly interest in local culture,' wrote John Cassidy in a profile in this week's New Yorker magazine.

'He is a rumpled but unflappable traveller, seemingly oblivious of bad weather, uncomfortable transportation and lack of sleep, as well as of the anti-war protesters who tend to appear wherever he goes.'

Closer to home, the scrutiny is stronger. Wolfowitz Watch, a website set up by the watchdog Bank Information Centre in 2005, has been a constant critic, publishing allegations of widespread distrust of the bank's president among staff. He has overlooked senior and qualified bank officials for promotion and instead appointed cronies and political allies, critics say, and has steered the policy of the bank, which lends US$22.5 billion annually to poor and developing nations, closer to the conservative ideals of the Bush White House.

'The concerns were that he would bring values that would promote multinational companies seeking profits at the expense of the people of those countries,' Ms Wood said.

'Those fears have come out. Overall there have been no surprises.

'There have been clever ideas from the World Bank, and pledges in the areas of climate change and carbon trading. One positive thing has been Wolfowitz working with the Liberian president on debt cancellation. I would give him a plus for that.

'But we've seen rhetoric and pledges. It remains to be seen if it results in debt cancellation.'