"Based on my experience with the administration in the months leading up to the war, I have little choice but to conclude that some of the intelligence related to Iraq's nuclear weapons program was twisted to exaggerate the Iraqi threat," Joseph Wilson, an international business consultant who served as Washington's ambassador to Gabon from 1992 to 1995, wrote in an opinion piece published Sunday in the New York Times.
Wilson, a career diplomat who served in the US foreign service from 1976 to 1998, was asked by the CIA to investigate reports that Niger in the 1990's sold Baghdad processed uranium that could be used to make nuclear weapons.
Wilson, who traveled to Niger in February 2002 concluded after spending eight days talking to dozens of people there that "it was highly doubtful that any such transaction had ever taken place."
Wilson said he presented his findings to the US ambassador to Niger, the CIA and the State Department African Affairs Bureau.
"Though I did not file a written report, there should be at least four documents in the United States government archives confirming my mission," he said. "While I have not seen any of these reports, I have spent enough time in government to know that this is standard operating procedure."
Wilson said he was surprised when, in December, the State Department published a fact sheet mentioning the Niger sale, and in January, President George W. Bush repeated the charges that Iraq tried to buy uranium from Africa.
"If my information was deemed inaccurate, I understand (though I would be very interested to know why.) If, however, the information was ignored because it did not fit certain preconceptions about Iraq, then a legitimate argument can be made that we went to war under false pretenses," Wilson wrote.
Niger's two uranium mines are run by French, Spanish, Japanese, German and Nigerian interests, Wilson wrote.
"If the government wanted to remove uranium from a mine, it would have to notify the consortium, which in turn is strictly monitored by the International Atomic Energy Agency.
"In short, there's simply too much oversight over too small an industry for a sale to have transpired," he said.
The chairman of the US Senate's Armed Services Committee later said Wilson's allegations were among many issues being reviewed by US lawmakers considering whether US prewar intelligence about Iraq's weapons program was manipulated or misinterpreted.
"All I can tell you right now is ... it is being ... objectively reviewed by the Senate in the Intelligence Committee," Senator John Warner told NBC television's "Meet the Press" program.