The CIA warned Britain that claims Iraq had tried to get uranium from Niger were false, months before the Government published the allegation in an intelligence dossier justifying military action against on Iraq.
The US intelligence agency asked a retired diplomat to investigate reports from Britain and Italy that Saddam had sought uranium for possible use in a nuclear weapon. The diplomat went to Niger in February 2002 and spoke to officials who denied having any uranium dealings with Iraq.
That information was shared with British officials, and was reported widely within the US government, a senior intelligence official in Washington told the Associated Press.
But the British government still included their information in a public statement on 24 September last year, citing intelligence sources, which said that Iraq "sought significant quantities of uranium from Africa."
That same day, an American intelligence official expressed doubts about the truth of the uranium reports during a closed session of the Senate Foreign Relations Committee.
Early this year, UN inspectors announced that the uranium reports were based primarily on forged documents initially obtained by European intelligence agencies.
The Washington Post, quoting unidentified US officials, reported today that the CIA did not pass on the detailed results of its investigation to the White House or other government agencies.
However, the US intelligence official who spoke to the AP, said the CIA's doubts were made known to other federal agencies through various internal communications, starting more than a year before the war began.
The reports first surfaced around the end of 2001, when the British and Italian governments told the United States they had intelligence that Iraq was seeking uranium from Niger. That uranium, once fully processed, could be used in a nuclear weapon.
At the time, the allies did not describe their sources, which turned out to be a series of letters purportedly between officials in Niger and Iraq, the intelligence official said.
The CIA distributed the Europeans' information to the rest of the government in early 2002 and noted that the allegations lacked "specifics and details and we're unable to corroborate them," the senior intelligence official said.
The CIA then asked the retired diplomat to investigate.
Other, fragmentary US intelligence also pointed to an Iraqi effort to acquire uranium in Africa. But the forged letters remained the key source, although it is unclear how much the CIA knew at this point about the original letters acquired by the European agencies.
A public report, gleaned from the classified intelligence estimate and published by the CIA in early October, made no mention of the specific uranium allegation. The CIA did not think the report was reliable enough to be included, the intelligence official said.
A former intelligence official at the State Department, Greg Thielmann, said the Niger uranium claim was long regarded with scepticism. Thielmann retired in September 2002.
However, the uranium report was published in a State Department fact sheet that was put out last December to cast doubt on Iraq's declaration to the UN that it had no prohibited weapons. The CIA tried unsuccessfully to have it edited out of the fact sheet before it was published, the official said.
It was omitted from future statements by State Department officials, including Secretary of State Colin Powell's address to the United Nations in February this year.