Manhattan's district attorney has asked the Iraq Oil-for-Food (search) probe to turn over documents as part of his criminal investigation into the former chief of the $64 billion program, he said Tuesday.

District Attorney Robert Morgenthau (search) told The Associated Press that he sent the letter to the U.N.-backed Independent Inquiry Committee seeking records it had gathered as part of its own separate investigation into Benon Sevan.

The committee, led by former Federal Reserve Chairman Paul Volcker (search), is investigating allegations of corruption in the 1996-2003 program, which aimed to help ordinary Iraqis suffering under U.N. sanctions imposed after Saddam Hussein's 1990 invasion of Kuwait,

In a February interim report, it found that Sevan's conduct in soliciting oil deals from Iraq was "ethically improper and seriously undermined the integrity of the United Nations." Volcker's team is expected to issue another report in the coming weeks that will delve deeper into Sevan's dealings with the program.

Morgenthau's parallel investigation of Sevan, a native of Cyprus, has been going for some time. He said he sent the letter in the "last couple of weeks" but would not divulge its contents or discuss possible charges against Sevan.

"It depends on what we find in the records," Morgenthau said.

U.N. spokeswoman Marie Okabe confirmed the letter was received, but would also not say when. She said the United Nations intends to cooperate. Volcker's committee will also cooperate as long as its own probe is not compromised, Volcker spokesman Mike Holtzman said.

Sevan's lawyer, Eric Lewis, did not return a phone call seeking comment, and Sevan did not answer a call to his New York home on Tuesday.