By Susannah Price
BBC correspondent at the United Nations
An inquiry into possible corrupt dealings in the defunct UN-administered Iraq oil-for-food programme says the allegations of misconduct are serious.
Iraq has some of the world's biggest oil reserves
The head of the investigation, Paul Volcker, says he will need $30m to complete the core investigation into the UN's role.
The multi-billion programme allowed Iraq to sell oil in order to buy humanitarian goods.
It was meant to ease the impact of sanctions on ordinary people.
It was the largest humanitarian operation ever undertaken by the UN.
Mr Volcker said the documents ran to millions of pages and thousands of contracts have been involved.
He said their aim was to put out the definitive report on the operation of programme, to be completed by the middle of next year.
The panel will also investigate what went on outside the UN as well.
The inquiry was launched after media reports accused individuals and companies from several countries of being involved in corruption and bribery in connection with oil sales.
The panel's report on the past three months was presented to UN Secretary General Kofi Annan last week.
It said the central issue to be addressed was whether there was any corruption or mal-administration by the United Nations, and whether any UN officials or contractors had engaged in illicit activities in connection with the programme.
Several US Congressional committees and Iraq's interim government have also launched their own investigations.