according to Ken Silverstein, he was this dude that 'Pakistani security forces' picked up in 2001, gave to the FBI...

Then this dude at the CIA said 'no we want him', they give him to egyptian intelligence, and the guy starts talking all sorts of crazy stuff.

"much of what he said, undoubtedly obtained under torture, was nonsense—including bogus information about collaboration between Al Qaeda and Saddam Hussein that soon found its way into then‒Secretary of State Colin Powell's notorious address to the United Nations."

July 2004 Newsweek:

"But more recently, sources said, U.S. interrogators went back to al-Libi with new evidence from other detainees that cast doubt on his claims. Al-Libi "subsequently recounted a different story," said one U.S. official. "It's not clear which version is correct. We are still sorting this out." Some officials now suspect that al-Libi, facing aggressive interrogation techniques, had previously said what U.S. officials wanted to hear."