A US TV network has revealed the name of "Curveball" - an Iraqi man whose information was central to the US government's argument to invade Iraq.
The programme says he arrived in a German refugee centre in 1999 where he lied to win asylum and was not the chemical expert he said he was.
His claims of mobile bio-weapons labs in Saddam Hussein's Iraq were backed until well after the 2003 invasion.
The CBS 60 Minutes programme airs on Sunday but material released on its web site says Curveball was "not only a liar, but also a thief and a poor student instead of the chemical engineering whiz he claimed to be".
"It was a guy trying to get his green card essentially, in Germany, and playing the system for what it was worth"
The CIA and French intelligence had turned the Iraqi foreign minister, yet instead we relied upon somebody lying for his green card.