A detailed review by the the Institute for Defense Analyses (sponsored by the Pentagon) of over 600,000 Iraqi documents, captured after the 2003 US invasion, has found no evidence that Saddam Hussein's regime had any operational links with Osama bin Laden's al-Qaida terrorist network.
The review, "Saddam and Terrorism: Emerging Insights from Captured Iraqi Documents", is not due to be published officially to Congress until tomorrow.
The Defence Secretary (Donald Rumsfeld) claimed in September 2002 that the United States had "bulletproof" evidence of cooperation between the al-Qaida and Saddam Hussein.
Secretary of State Colin Powell claimed that there were many links between Saddam and al-Qaida in a February 2003 speech to the United Nations Security Council designed to rally support for the invasion.
Seemingly all of these statements made by Rumsfeld and Powell were based on false/misinterpreted intelligence.
The review was completed last year. However, it has been sat on since then as people have been reluctant to declassify it.