The disputed documents were first provided to Italian intelligence services in late 2001, and information about them was then passed along to allied intelligence agencies, including Britain's MI6 and the CIA.

But the documents themselves didn't come into the possession of the U.S. government until nearly a year later, in October 2002, sources said, when a foreign individual--described by one source as a journalist--turned them over to the U.S. Embassy in Rome. The motivations of the foreign journalist are unclear but one U.S. intelligence official says he "may have been looking for money"--either for himself or a source who provided the material to him. (The sources did not disclose the identify of the journalist.)

All sources agree that the U.S. Embassy did not in fact pay for the material. What is most baffling, however, is what happened after that.

The U.S. Embassy quickly passed the documents along to the CIA station chief in Rome--as well as the State Department's Office of Intelligence and Research. But the station chief didn't send them along to CIA headquarters in Langley, Va., apparently believing they were being sent instead through State Department channels.

In fact, CIA headquarters--including its nuclear-weapons analysts--never got the documents until four months later, in early February 2003--well after CIA officials and White House aides had already had several discussions about whether the information about Iraqi attempts to buy Niger uranium was reliable enough to be mentioned by the president in his Jan. 28 State of the Union address.

Two sources said, at one point, State Department's INR division--which had long since concluded there was no reliable evidence that Iraq had reconstituted its nuclear weapons program--offered the documents to the CIA.