The United Nations Oil For Food programme that operated in Iraq is facing fresh corruption allegations.
A committee investigating possible wrongdoing has said that the programme's chief, Benon Sevan, received almost $150,000 in bribes.
Mr Sevan, who resigned from the UN on Sunday, denies any wrongdoing.
Another UN official, Alexander Yakovlev, has pleaded guilty in a US federal court to bribery charges as a result of the investigation.
UN spokesman Mark Malloch Brown said the developments reflected badly on the organisation but also on the governments involved.