Investigators looking into corruption allegations in the U.N. Oil-for-Food (search) program in Iraq are seeking to verify a Swiss firm's claims that it paid Secretary General Kofi Annan's (search) son approximately $365,000 over eight years.

Former U.S. Federal Reserve Chairman Paul Volcker, (search) who is conducting the independent investigation into the $64 billion program, asked Cotecna (search) Inspection S.A. about a month and a half ago for records of its transactions with five companies for the years 1996 to 2004, Seth Goldschlager, a Cotecna spokesman, said Thursday.

Kojo Annan (search), the son of the U.N. chief, worked for Cotecna in West Africa from 1995 to December 1997 and then as a consultant until the end of 1998, when the company was awarded a contract to certify the import of goods under the oil-for-food program.

He and Cotecna both deny any link between his employment and the awarding of the U.N. contract.

Goldschlager said Kojo Annan earned a total of about $200,000 through 1998 from Cotecna, then was paid $2,500 a month from 1999 until February 2004 not to work for a competing company in Nigeria or Ghana. With expenses for a transition period, the total estimated by Cotecna during this so-called "noncompete" contract is estimated now at somewhat above $165,000, Goldschlager said in an interview.

"Cotecna said we can't do this quickly, so why don't we get an auditor to do this and we'll pay for it and you choose the auditor," Goldschlager said in an interview.

But there was a delay in selecting an auditor, and the Swiss accounting firm BDO Visura, which was ultimately chosen by Volcker's Independent Inquiry Committee, only began work about a week ago and won't be finished with the audit until the end of April, he said.

He also said the company won agreement from Swiss banks to drop secrecy provisions regarding Cotecna transactions with the five companies.

"They're looking for anything in the accounts of these five companies that could have had anything to do with the U.N. Oil-for-Food program," he said.

A spokesman for the Volcker inquiry said he had no comment on specifics of the investigation raised by Goldschlager and refused to allow the use of his name.

Cotecna gave its first estimate of Kojo Annan's earnings after The Financial Times and Italian business newspaper Il Sole 24 published an estimate that he had earned at least $300,000 from the company, almost double the amount previously disclosed.

Volcker is scheduled to release an interim report on Tuesday detailing his findings about whether or not Kofi Annan or Kojo Annan committed any wrongdoing in connection with the Oil-for-Food program.

Since the audit won't be completed until the end of April, however, it appears that Volcker will not be able to make a final assessment in his upcoming report. His final report is expected in midsummer.

The Oil-for-Food program, which ran from 1996 to 2003, allowed the former Iraqi government to sell oil in exchange for humanitarian goods, as an exemption from U.N. sanctions imposed after Saddam Hussein's 1990 invasion of Kuwait.

In a bid to curry favor and end sanctions, Saddam allegedly gave former government officials, activists, journalists and U.N. officials vouchers for Iraqi oil that could then be resold at a profit.