NEW YORK -- Jules B. Kroll, Wall Street's premier private eye, has snooped for dirt on such nefarious figures as Haitian dictator Jean-Claude "Baby Doc" Duvalier, Filipino autocrat Ferdinand Marcos, and convicted stock swindler Ivan F. Boesky.

But Kroll's latest case promises to be his most celebrated. Not only does it involve a huge amount of money -- more than $10 billion -- but the target is one of the most notorious villains in decades, none other than Saddam Hussein.

Hired by the Kuwaiti government last October to "get the goods" on Saddam's hidden wealth, Kroll's company used its experience in financial sleuthing, giant computerized databases and far-flung contacts from Jordan to Panama to achieve startling results.

In a report made public over the weekend, Kroll said that Saddam has systematically skimmed money off of Iraq's oil sales and other business deals and had squirreled away billions of dollars in more than 40 banks around the world.

Using front companies set up by relatives or other cronies, Kroll found, Saddam had gained an indirect, 8.4 percent stake in the French company Hachette, which publishes such well-known American magazines as Car and Driver and Woman's Day.

"It's the kind of work that we've worked almost 19 years to perfect, and we're pretty good at it," said Kroll, president and founder of Kroll Associates, the world's largest corporate investigations firm.

Since it was founded in 1972, the firm has grown to a staff of 250 based in eight offices in the United States, Western Europe and Hong Kong, and has annual revenue of about $50 million. Among its investigators are ex-prosecutors, journalists, FBI agents and a former New York police chief.

While the Saddam case is nowhere close to the most lucrative that the firm has taken on, it probably is the most important "in terms of international significance," Kroll said in a telephone interview.

"Right now, this is the ogre of the moment. This man has been terrorizing the world for quite some time, and now he's had his comeuppance," Kroll said.

Saddam's grave miscalculation in invading Kuwait and his brutal treatment even of Iraqis who worked for him played a critical role in enabling Kroll's team of 20 to 30 investigators to track down the dictator's wealth, Kroll said.

The most lucrative source of information by far about Saddam's hidden billions came from "hundreds upon hundreds of Iraqi expatriates whose families have been brutalized by this regime," he said. Many of these expatriates had been business agents for Saddam's clandestine network of financial holdings, but turned against him after the invasion of Kuwait.

That is a "typical pattern" in investigations of dictators' wealth, he added. "It was true with Marcos. It was true with Duvalier. It was true here. Generally, when you have a dictatorship that brutalizes families over generations, they take care of their friends, but they also build a lot of enemies," he said.

The Kuwaitis want to track down Saddam's wealth principally because they hope to get their hands on it to cover reparations for damage caused by Iraq during its occupation of Kuwait. Kroll's investigation still has far to go, but the initial results were made public in part to put pressure on various governments to move against Saddam's assets.

Kroll's firm is the leader in a business that has grown rapidly in recent years, owing to trends ranging from the increase in hostile corporate takeovers to the rise in the counterfeiting of artwork. Although Kroll's firm prides itself on relying only on legal methods, its activities have occasionally caused controversy.

A Texas judge temporarily barred Kroll once from pursuing an aggressive investigation into corporate raider T. Boone Pickens. Kroll also worked for years for Drexel Burnham Lambert Inc., the now-bankrupt securities firm that later pleaded guilty to securities fraud and whose star executive Michael Milken is now serving a 10-year jail sentence.

Kroll, 49, launched his company after an unsuccessful bid to get ahead in New York Democratic Party politics. After working for Robert F. Kennedy's Senate office when he was in Georgetown Law School in the 1960s and serving briefly as an assistant prosecutor in the Manhattan district attorney's office, Kroll was defeated when he ran for the New York City Council as a reformist candidate from Queens in 1971.

He launched the investigations firm a year later, starting out by combating waste and fraud in the printing industry, which he knew because his father had owned a medium-sized printing firm. Kroll Associates struggled for a while, but business picked up after 1978 when Kroll hired a former FBI agent, Bill Kish, to run investigative operations.

In a typical Kroll case, a big corporation will hire the firm to investigate whether a potential business partner has sufficient assets for the deal -- or a record of lawsuits or unsavory connections with organized crime.

The firm also looks into suspected cases of embezzlement by corporate employees and of theft of trade secrets by rivals.

John C. Wilcox, managing director of Georgeson & Co., a firm that specializes in advising companies engaged in "proxy fights" -- or battles for shareholder support when control of a company is at stake -- said he has recommended that clients hire Kroll when confidential research is needed.

In one case about five years ago, Wilcox recalled, an investigation by Kroll uncovered "personal philandering" and "some shady deals" on the part of a leader of a group of dissident shareholders who were considering launching a hostile takeover of a company that Wilcox declined to identify. When the company's management threatened to make public the data gathered by Kroll, the dissidents quickly dropped their plans.

"Sometimes a client comes to us, and says, 'Gee, this {deal} doesn't pass the smell test, what can we do about it?' and we say, 'Go to Jules Kroll,' " Wilcox said.