"We have found in each case that the procurement process was tainted, failing to follow the established rules of the organisation designed to assure fairness and accountability," former US Federal Reserve Chairman Paul Volcker wrote in Thursday's Wall Street Journal editorial page.

But Volcker said the administration of the programme appeared to be "free of systematic or widespread abuse."

Volcker was appointed by the United Nations to head an independent inquiry into the now-defunct $67 billion program that was intended to ease the hardship of ordinary Iraqis under 1990 UN sanctions.

Volcker intends to release a preliminary report on the progra-mme last afternoon and a final one in June.

"The findings do not make for pleasant reading," he said.

But he said that allegations of conflict of interest by Secretary General Kofi Annan, whose son Kojo had worked in West Africa for a firm under contract to the United Nations in Iraq, would not be part of a preliminary report.

Most damning for the world body is Volcker's description of Benon Sevan, the UN undersecretary-general in charge of the UN programme, who is accused of steering oil contracts to a firm in the Middle East.

In documents Iraq released after the fall of Saddam Hussein, Sevan is accused of asking Iraq to give an oil contract to Africa Middle East Petroleum, a Swiss-based oil trading company.