United Nations ? Investigators probing the U.N. oil-for-food program said Tuesday that Secretary-General Kofi Annan didn’t interfere in the awarding of a contract to a company that employed his son but criticized the U.N. chief for not properly investigating possible conflicts of interest.

A defiant Annan said “Hell no” when asked at a news conference if he would resign, noting the report’s findings that he committed no wrongdoing.

“After so many distressing and untrue allegations have been made against me, this exoneration by the independent inquiry obviously comes as a great relief,” he said.

Although the report did not completely vindicate the secretary-general, the investigation led by former U.S. Federal Reserve Chairman Paul Volcker said there was insufficient evidence to show that he was aware of the bid.

Still, the report raised questions about when the secretary-general learned about the December 1998 contract to the Swiss firm, Cotecna Inspection S.A., and strongly criticized the destruction of documents by his former chief of staff that could have shed light on the oil-for-food scandal in Saddam Hussein’s Iraq.

The independent inquiry, released Tuesday, faulted Annan for conducting a one-day investigation into the matter, saying it should have been a more rigorous, independent probe.

It also accused the company, Cotecna Inspection S.A., and Annan’s son, Kojo, of trying to conceal their relationship after the firm was awarded the contract.

Although Tuesday’s report found no wrongdoing by Kofi Annan, it clearly faulted the secretary-general’s management of the world body and his oversight of the oil-for-food program.

The $64 billion oil-for-food program was the largest U.N. humanitarian aid operation, running in 1996-2003. Saddam’s government was allowed to sell oil in exchange for humanitarian goods as an exemption from U.N. sanctions imposed after Iraq’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. U.S. congressional investigators say Saddam’s regime may have illegally made more than $21 billion by cheating the program and other sanctions-busting schemes.