Iraq's parliament has asked the United Nations for help to track down about $18bn of Iraqi oil money it says was stolen after the 2003 US-led invasion.
In a letter to the UN office in Baghdad last month, parliament's Integrity Committee asked for help to find and
recover the oil money taken from the Development Fund of Iraq (DFI) in 2004 and lost in the chaos that followed the invasion.
In 2004, the Bush administration flew billions of dollars in cash into Iraq. The money came from the sale of Iraqi oil, surplus funds from the UN oil-for-food programme and seized Iraqi assets.
The DFI was established in 2003 at the request of the Coalition Provisional Authority (CPA), the US body headed by Paul Bremer that governed Iraq after the invasion.
The fund was to be used to pay the salaries and pensions of Iraqi government workers and for reconstruction projects.
"All indications are that the institutions of the United States of America committed financial corruption by stealing the money of the Iraqi people, which was allocated to develop Iraq," said the letter sent to the UN with a 50-page report.
The committee called the disappearance of the money a "financial crime" but said UN Security Council resolutions prevent Iraq from making a claim against the US.
Far higher figure
Osama al-Nujaifi, the Iraqi parliament speaker, has told Al Jazeera that the amount of Iraqi money unaccounted for by the US is $18.7bn - three times more than the reported $6.6bn.
US diplomat defends Iraq's case
Al-Nujaifi is scheduled to visit the US soon and discuss the missing Iraqi billions.
He said that he received a report this week based on information from US and Iraqi auditors that the amount of money withdrawn from a fund from Iraqi oil proceeds, but unaccounted for, is much more than the $6.6bn reported missing last week.
"There is a lot of money missing during the first American administration of Iraqi money in the first year of occupation.
"Iraq's development fund has lost around $18bn of Iraqi money in these operations - their location is unknown. Also missing are the documents of expenditure.
"I think it will be discussed soon. There should be an answer to where has Iraqi money gone."
The appeal to the United Nations could help Iraq recover its money by putting its case before the international community, Bahaa al-Araji, the head of the parliamentary Integrity Committee, said.
"We cannot sue the Americans. Laws do not allow us to do that. All we want is to get this issue to the UN," he said. "If this works, it will open the way for Iraq to restore its stolen money."
The Los Angeles Times newspaper reported last week that Iraqi officials argue that the US government was supposed to safeguard the stash under a 2004 legal agreement it signed with Iraq, hence making the US responsible for the cash that has disappeared.
Pentagon officials have contended for the last six years that they could account for the money if given enough time to track down the records.
The US has audited the money three times, but has still not been able to say exactly where it went.
Al Jazeera's Iraq correspondent, Jane Arraf, reporting from Baghdad, said: "It's an absolutely astonishing figure - this goes back to 2003 and 2004.
"There is going to be a fairly wide net cast - some of them [involved in mishandling of this money] are thought to be US officials, but many here believe that it is the Iraqis who have filled their pockets.
"Safeguarding the money was up to the Americans ... after the invasion, coalition provisional authority (CPA) here was run by the American military.
"Piles and piles of shrink-wrapped US dollars came here, but the cash coming in is not the important part - it is what happened to it after [it got here].
"There are no documents to indicate who got it, where it was spent and what was ever built from it."