Experienced intelligence officers repeatedly knocked down those reports, sometimes after painstaking inquiry.
But like the carnival game "Whack-a-Mole," similar reports kept popping back up in different places. The unconfirmed reports were embraced by the White House, which began to repeatedly warn that Iraq was trying to build nuclear weapons.
Those warnings in turn played a crucial role in sending America to war. They also sparked a political and intelligence scandal that still roils the Bush administration.
A review by the Los Angeles Times of those seemingly independent intelligence reports leads to the conclusion that they were based on information contained in forged documents that an Italian ex-spy was trying to sell to Western intelligence agencies in 2001 and 2002.
The story refused to die for several reasons, including a strong appetite in the Pentagon and the White House for information that supported a case for war, and a widely recognized phenomenon in the intelligence field in which bad information, when repeated by multiple sources, appears to be corroborated.
"This became a classic case of circular reporting," said a U.S. intelligence official who spoke on condition of anonymity because he is not authorized to talk to reporters. "It seemed like we were hearing it from lots of places. People didn't realize it was the same bad information coming in different doors."