A commission investigating the U.N.'s Iraq oil-for-food program is questioning Secretary-General Kofi Annan about his involvement.  The commission's interim report, originally due for release this month, has been delayed.

Former U.S. central bank chief Paul Volcker and members of his oil-for-food commission interviewed Secretary-General Annan for more than 90 minutes Tuesday.

U.N. spokesman Fred Eckhard says Mr. Annan is cooperating with the Volcker probe.

"He has met more than once for an extended period of time with Mr. Volcker and his investigators, so yes, the secretary-general is part of the investigation, is a subject like anyone else involved in the oil for food in the secretariat," he said.

Neither spokesman Eckhard nor Mr. Volcker gave details of the meeting.

Oil-for-food was the largest humanitarian program ever set up by the United Nations. It was intended to ease the pain of U.N. sanctions imposed on Saddam Hussein's government after the 1990 invasion of Kuwait on ordinary Iraqis.

Internal audits released by the Volcker Commission this month reveal gross mismanagement by U.N. administrators.

An interim report focusing on responsibility for administrative failures was due out this month. But after meeting the secretary-general Tuesday, Mr. Volcker said the release would be delayed until sometime in February.

In separate comments late last year, he said his investigation was proving much more difficult than he had expected.

"As we get into it, everything gets more complicated rather than less,” he added.  “We turn over one page and you find several other pages that lead to investigatory questions so this is a complicated process."

Mr. Volcker again Tuesday stressed that his mandate is to investigate U.N. responsibility for failures in the oil-for-food program.

Secretary-General Annan named him to head a three-man panel last year after allegations of widespread fraud surfaced in the administration of the $64 billion program.

Five U.S. congressional committees are also looking into various other aspects of the oil-for-food scandal.   The chairman of one committee, Republican Senator Norm Coleman, has said Secretary-General Annan should be held accountable, and should resign.

U.S. Attorney General John Ashcroft last week announced the first conviction related to the case.
 
He said an Iraqi-American businessman had pleaded guilty to secretly working for Saddam Hussein's government to lobby American and U.N. officials about ending sanctions. For his work, the businessman said he had received the rights to sell millions of barrels of Iraqi oil.

A CIA report last year estimated that Saddam used the oil-for-food program to generate illegal kickbacks totaling $1.7 billion.