Allegations that French officials were offered bribes by Saddam Hussein are unverified, France has said.
Oil is Iraq's most valuable asset
An official US report said that the former Iraqi leader sought to influence world figures with "oil vouchers" in an attempt to get UN sanctions lifted.
French businessmen and politicians were among the recipients, it said.
The report, which found Iraq had no weapons of mass destruction at the time of the US-led invasion, has fuelled the debate about justification for the war.
The BBC's David Bamford says that on the face of it, the ISG's evidence about alleged bribery looks startling - but it remains a long way from being proof.
The "known oil voucher recipients" listed relate to some 40 different countries, whose names are said to have been obtained from two senior Iraqi officials captured last summer.
According to the ISG's findings, Saddam Hussein particularly targeted officials from France, Russia and China - whose governments have the power of veto on the UN Security Council and opposed the war.
The report, published on the CIA's website, claims the French recipients included the former Interior Minister Charles Pasqua and businessman Patrick Maugein - both of whom deny the allegations.
Other officials include Russian politician Vladimir Zhirinovsky and Benon Sevan, the former head of the oil for food programme for Iraq, who have also denied accepting bribes.
The report does not say if any attempt was made to verify the data, and notes that some vouchers were issued legitimately.
The French foreign ministry said that it was important to first discover if there was any truth behind the accusations.
"As far as we understand it, the accusations... are unverified either with the persons concerned or the authorities of the countries concerned," spokesman Herve Ladsous said.
The BBC's Caroline Wyatt in Paris says France appears to view the US accusations as at least partly politically-motivated, following its opposition to the war on Iraq.
But she also notes that it is well-known that many French politicians and businessmen used to enjoy friendly relations with Saddam Hussein's government.
Saddam's government suffered international sanctions after the 1990 invasion of Kuwait
Names of US companies or citizens found on the secret Iraqi lists were left out of the report on grounds of the US Privacy Act, the ISG report notes.
The US-led coalition that invaded Iraq said allegations of Iraqi WMDs were a key reason for going to war.
Chief US weapons inspector Charles Duelfer, who heads the Iraq Survey Group (ISG), said in the report that Iraq had no stockpiles of biological, chemical or nuclear weapons before last year's invasion.
Iraq's nuclear capability had decayed rather than grown since the 1991 Gulf War, he added.
However, the report also said there was evidence that Saddam Hussein had intended to resume a weapons programme.