The claim that Saddam Hussein was able to deploy chemical or biological weapons within 45 minutes of the order being given was a headline-grabbing assertion in a British government dossier published in September 2002, in the run-up to the Iraq war.
It was also at the heart of a row between the British government and the BBC over allegations that Downing Street "sexed up" intelligence on Iraq's weapons ahead of the war.
But Nick Theros the Washington representative of Iyad Allawi, who headed the Iraqi National Accord in exile and is now a member of the Iraqi governing council in Baghdad, said the 45-minute claim was raw information from a single source, part of a large amount of information passed on by the INA to British intelligence.
Theros told the Guardian: "We were passing it on in good faith. It was for the intelligence services to verify it."
Theros said the information now seemed to be baseless, a "crock of shit". "Clearly we have not found WMD," he said, referring to Iraq's alleged weapons of mass destruction.
Saddam's refusal to give up the pursuit of such banned arms was cited by Britain and the United States as a main justification for war.
Theros said the Iraqi officer who claims to have been the original source of the intelligence passed on by the INA had in fact never seen purported chemical weapons crates upon which his 45-minute claim was based.
On Wednesday, a senior British judge is to deliver a long awaited report on the suicide of David Kelly, the weapons expert at the centre of allegations that Downing Street embellished intelligence ahead of the Iraq conflict.