WASHINGTON – Inquiries into Iraq’s oil-for-food program are turning into full-fledged criminal investigations of foreign and domestic companies suspected of enriching Saddam Hussein under the cover of assistance to the Iraqi people.

The New York Sun has learned of three separate federal investigations into foreign and domestic banks and companies that could lead to serious charges against individuals who participated in Saddam’s multibillion-dollar swindle. Already under way are investigations from U.S. attorneys in the District of Columbia, New York, and Texas, according to sources familiar with these tightly held probes.

The Sun learned of the federal investigations as congressional investigators began poring through a new batch of documents from a French bank, which held in escrow $60 billion in Iraqi oil revenues in trust for the U.N. oil-for-food program. The bank in question, BNP Paribas, has released a statement saying it is not the target of any investigations but plans to cooperate with congressional committees investigating the matter.

The bank has already received subpoenas from both the Senate and House governmental affairs committees, which are conducting concurrent investigations into the banks and companies that worked with Saddam’s Iraq when he was supposed to be using his oil revenues for food and medicine only.

In the past year, documents have come to light suggesting that most of the contracts for food and medicine that Saddam offered were for shoddy goods paid for at inflated prices, the hallmarks of a kickback scheme.

In January, a new Iraqi newspaper, al-Mada, published a list of 270 companies and 50 people who it said received vouchers from Saddam Hussein to purchase oil. Congressional sources said they are looking into the list, but insist that these are only allegations and the list is not the sole basis of the investigations.

With three federal investigations, companies and business people that benefited from Saddam’s corruption could be facing stiff penalties and even prison time. Sources familiar with the federal probes would not disclose the targets of the investigations, but did say that U.S. attorneys were looking into some American companies and their role in the oil-for-food program.

Two sources said attorneys were investigating possible violations of the USA Patriot Act and the Foreign Corrupt Practices Act. Companies that participated in a scheme to bribe Iraqi officials could also be in violation of federal laws that prohibit fraud through interstate commerce.

“Under the definition of mail and wire fraud, all you need is a scheme that is vaguely dishonest and it can be indicted,” a criminal defense lawyer headquartered in Boston who is an expert in federal fraud statutes, Harvey Silverglate, said in an interview yester day. “In my view, a violation of U.N. rules could be seen as a crime in the facility of interstate commerce, through the phone or mail. If foreign companies have used the means of interstate communications in fraud, then they could be indicted.”

While the three federal investigations are not directly related to congressional inquiries into corruption in the oil-for-food program, evidence collected by congressional panels could be used by federal prosecutors to advance their investigations, and sources close to the investigations said investigators have been willing to share information.

There is a precedent for such cooperation. The permanent subcommittee on investigations of the Senate Committee on Government Affairs recommended the indictment of Riggs Bank in connection with its inquiry into the bank’s alleged hiding of money for Third World dictators.

“This is a very comprehensive investigation from the permanent subcommittee on investigations,” a spokesman for Senator Coleman, a Republican of Minnesota, told the Sun yesterday. Mr. Coleman is chairman of that subcommittee.

“Senator Coleman has reiterated that he will follow the money wherever it leads, to corporations, the United Nations and even to countries. Wherever the money trail leads,” the spokesman said.

The spokesman, Tom Steward, also said Mr. Coleman’s investigators are in possession of more than a million pages of documents. That panel has an FBI agent and two IRS officials working on its probe. Already, according to a Senate staff member, the panel has sent out at least six subpoenas for records and 12 letters to potential witnesses who have said they would cooperate with the probe.

Two companies said to be cooperating with the Coleman investigation are BNP-Paribas and Cotecna, a consulting firm that the United Nations used to certify that food and medicine Iraq purchased with its oil revenues had arrived in the country. This spring, news reports disclosed that Cotecna had hired U.N. Secretary-General Annan’s son Kojo between 1995 and 1998.

The House counterpart of the Senate committee is also looking into BNPParibas and Cotecna. Rep. Christopher Shays, the Republican from Connecticut who is chairman of that panel, has promised hearings next month on the oil-for-food program. Mr. Coleman’s committee is trying to schedule hearings for November.

A spokesman for the House International Relations Committee told the Associated Press yesterday, “The subpoena for BNP Paribas stems from concerns expressed about the bank’s compliance with existing ‘know your customer’ rules and similar laws enacted as part of the Patriot Act.”

The new records submitted by the French bank could open up further leads for investigators as the bank’s records would provide further detail into how Iraq’s oil money was spent under the U.N. program.