The independent inquiry committee in charge of investigating alleged corruption in the United Nation's oil-for-food programme is facing continued difficulties in winning co-operation from Russia, officials close to the investigation have said.

According to an official acquainted with the matter, most countries have offered strong expressions of co-operation with the commission, headed by Paul Volcker, a former chairman of the US Federal Reserve. Both France and the UK said on Wednesday that they had signed memoranda of understanding to help it in its work.