It is possible a fabricated story of biological weapons drove the U.S argument for the 2003 invasion of Iraq.
U.S television network CBS says it has identified an Iraqi defector named Rafid Ahmed Alwan, who gave intelligence information to German and U.S investigators.
Mr Alwan arrived at a German refugee centre in 1999, where he allegedly lied about being a chemical engineer in charge of a facility making mobile biological weapons.
He was eventually interviewed by German intelligence and was able to provide credible descriptions of the Djerf al-Nadaf plant because he had actually worked there, albeit not as head of a biological weapons program.
Summaries of his debriefings were sent to the CIA and then became the main platform for the U.S decision to invade Iraq.
The information was passed to then secretary of state Colin Powell to use at the United Nations in a major speech justifying military action against Iraq.
CBS says Mr Alwan is now believed to be living freely in Germany, probably under an assumed name.