'The extent of the corruption is staggering,'' Sen. Norm Coleman told me. He is a freshman Republican from Minnesota completing his second year in Washington, and he was talking about the United Nations and its pious secretary-general, Kofi Annan. Coleman's comments are not the mere musings of an insignificant rookie senator, but the considered judgment of a committee chairman whose careful investigation reached the hearing stage today...

...Coleman said this week's hearings will show that ''the scope of the ripoff'' at the U.N. is substantially more than the widely reported $10 billion to $11 billion in graft. But more than money is involved. These hearings also should expose the arrogance of the secretary-general and his bureaucracy. At the same time that he has refused to honor the Senate committee's request for documents, Annan has inveighed against the Fallujah offensive sanctioned by the new Iraqi government while ignoring the terrorism of insurgents. This is an unprecedented showdown between a branch of the U.S. government and the U.N.

The scandal is not complicated. Money from Iraqi oil sales permitted by the Saddam Hussein regime under U.N. auspices, supposedly to provide food for Iraqis, was siphoned off to middlemen. Billions intended to purchase food wound up in Saddam's hands for the purpose of buying conventional weapons. The complicity of U.N. member states France and Russia is pointed to by the Senate investigation. The web of corruption deepened when it was revealed that Annan's son, Kojo, was on the payroll of a contractor in the oil-for-food program...

...Coleman has been joined in rare bipartisan cooperation by the subcommittee's fiercely liberal ranking Democrat, Sen. Carl Levin of Michigan. Coleman sent Levin a draft of a tough letter to Annan, and Levin signed it. The bipartisan letter demanded access to U.N. internal audits and key U.N. personnel. It also accused the Volcker committee of ''affirmatively preventing the subcommittee'' from investigating the scandal. A major point of dispute is the U.N.'s flat refusal to permit Lloyd's Register, hired by the U.N. to inspect Iraq's oil-for-food transactions, to provide any documents to the Senate.

The reaction by the U.N. bureaucracy has been an intransigent defense of its stone wall. Edward Mortimer, Annan's director of communications, publicly sneered at the Coleman-Levin letter as ''very awkward and troubling.'' Privately, Annan's aides told reporters that they were not about to hand over confidential documents to the Russian Duma and every other parliamentary body in the world.

But the U.S. Senate is not the Russian Duma. These are not just a few right-wing voices in the wilderness who are confronting Kofi Annan. ''In seeing what is happening at the U.N.,'' Coleman told me, ''I am more troubled today than ever. I see a sinkhole of corruption.'' The United Nations and its secretary-general are in a world of trouble.

WASHINGTON (AP) -- Saddam Hussein's regime made more than $21.3 billion in illegal revenue by subverting the U.N. oil-for-food program -- more than double previous estimates, according to congressional investigators.

"This is like an onion -- we just keep uncovering more layers and more layers," said Sen. Norm Coleman, R-Minnesota, whose Senate Committee on Government Affairs received the new information at hearing Monday.

The new figures on Iraq's alleged surcharges, kickbacks and oil-smuggling are based on troves of new documents obtained by the committee's investigative panel, Coleman told reporters before the hearing...