Investigators probing allegations of impropriety in the United Nations' Iraqi Oil-for-Food program questioned Secretary-General Kofi Annan (search) about his involvement twice last year and again Tuesday, a U.N. spokesman said.

Annan met with former Fed Chairman Paul Volcker (search) and his investigators Nov. 9 and again Dec. 3, spokesman Fred Eckhard said. A third meeting took place Tuesday afternoon, but Volcker, who spoke to reporters as he left the United Nations, would not give details.

Volcker's panel had been expected to release a preliminary report in late January, but he said Tuesday it would come out in early February. "We're going to have a report shortly," he said. "All I can tell you is wait for the report to come out."

The Independent Inquiry Committee is investigating whether U.N. administrators took bribes and allowed Saddam Hussein (search) to skim money from the Oil-for-Food program. Begun in December 1996, the program allowed Saddam's regime to sell unlimited quantities of oil on condition the money went primarily to buy food, medicine and other humanitarian goods for Iraqis and pay reparations to victims of the 1991 Gulf War.

Tuesday was the first time U.N. officials confirmed Annan had met with Volcker's panel, though it had been expected.

"The secretary-general is part of the investigation, is a subject like anyone else involved in Oil-for-Food at the secretariat," Eckhard said.

One element of the investigation is Annan's son Kojo, who worked in Africa for a Swiss company that had a contract under the Oil-for-Food program. Kojo Annan, who denies any involvement in wrongdoing, received payments for more than four years after his job ended.

It was not immediately known if the U.N. chief discussed his son during his meetings with Volcker and other investigators. Eckhard said the November meeting lasted more than 11/2 hours and the second about 25 minutes.

A report in October by top U.S. arms inspector Charles Duelfer said Saddam was able to "subvert" the $60 billion program to generate an estimated $1.7 billion in revenue outside U.N. control from 1997 to 2003.

Saddam also raked in more than $8 billion from illicit oil deals with Jordan, Syria, Turkey and Egypt, according to U.S. congressional investigators.

The report alleged Saddam issued secret vouchers for the purchase of Iraqi oil to U.N. officials and an array of officials and political figures from various countries — especially France, Russia and China — reportedly to curry favor with key Security Council members. That oil could then be resold at a profit.

There are also at least five U.S. congressional probes into the scandal, which has been a major blow to the United Nations and has led some to call for Annan's resignation.