Updated

The U.N. procurement official who has been at the center of a FOX News investigation into a possible conflict of interest involving his son has quit his job, officials at the United Nations confirmed Wednesday.

Alexander Yakovlev (search), a Russian who was a longtime U.N. employee, submitted his resignation Tuesday and U.N. officials accepted it Wednesday. The resignation was immediate.

But Yakovlev's decision to leave on his own terms will not stop the U.N. investigation into his activities, according to a statement from a spokesman for Secretary-General Kofi Annan.

And, the Independent Inquiry Committee — the panel investigating the Oil-for-Food (search) program — asked for and received U.N. permission to seal Yakovlev's office to access materials that might fit with its broader probe into corruption at the organization.

Testimony by Yakovlev was important in two interim reports by the IIC, which is headed by Paul Volcker, about the scandal-scarred Oil-for-Food program.

On Monday, the United Nations announced it was going to look into whether Yakovlev violated conflict-of-interest rules. But the U.N. decision did more than draw attention to the man's possible wrongdoing — it also raised questions about how the world body investigates itself.

The decision to investigate Yakovlev was prompted by a FOX News investigation into the staffer. Yakovlev, who handles tens of millions of dollars' worth of contracts for a variety of U.N. operations, is entwined in an apparent father-son conflict of interest similar to the one that engulfed Secretary-General Kofi Annan (search) and his son Kojo.

Yakovlev's son, Dmitry, worked for a company called IHC Services, Ltd. (search), and the firm represents companies trying to secure U.N. contracts.

IHC's Chief Executive Officer Ezio Testa told FOX News that he gave Dmitry Yakovlev a job because his father asked him to, a move that came only months after the older Yakovlev worked on a $1.2 million procurement contract with the company.

After the FOX News report, which was published Monday, the United Nations said its Office of Internal Oversight Services is probing Yakovlev. But U.N. officials revealed little else about the investigation, except that it is confined to the conflict-of-interest allegation. According to a U.N. spokesman, Yakovlev will continue to work during the investigation.

The most recent head of the Office of Internal Oversight Services, Dileep Nair (search), is under investigation himself for charges of sexually harassing staff; his replacement is not scheduled to take over until mid-July.

FOX News' own investigation raised questions that went beyond the father-son relationship with IHC, including the discovery that Alexander Yakovlev's wife, Olga, was issued a Visa credit card from a bank in the Caribbean country of Antigua and Barbuda, which has strict bank secrecy laws.

The card was in the name of a company called Moxyco Ltd., and was supplied to Olga Yakovlev by Maritime International, a firm that helps individuals create offshore corporations and bank accounts. When FOX News tried to obtain an explanation from her about this financial arrangement, Olga Yakovlev said to talk to her husband, who will not agree to an interview unless Annan permits him to. That permission has not yet been granted.