The US official running Iraq appears to have contradicted Tony Blair's claim Saddam Hussein had laboratories for developing weapons of mass destruction.
Bremer said Blair's remarks sounded like a "red herring"
The prime minister said in a Christmas message to UK troops that the Iraq Survey Group (ISG) had unearthed "massive evidence" of clandestine labs.
The head of the Coalition Provisional Authority said it was not true.
Paul Bremer said it sounded like a "red herring" made up by someone to upset the rebuilding effort.
But Mr Bremer seems to have been unaware that the quotes had come from Mr Blair when they were put to him in an interview on ITV1's Jonathan Dimbleby programme.
"I don't know where those words come from but that is not what (ISG chief) David Kay has said," he said.
"I have read his reports so I don't know who said that.
"It sounds like a bit of a red herring to me.
It sounds like someone who
doesn't agree with the policy sets up a red herring then knocks it down."
However when it was pointed out the remarks had come from the leader of the US's closest ally, Mr Bremer seemed to pull back from his original remarks.
"There is actually a lot of evidence that had been made public," he said
Former chief UN weapons inspector Hans Blix has also cast doubt on Mr Blair's assertion.
Dr Blix said it was "innuendo" to suggest laboratories were used for WMD.
However on Sunday, Downing Street was standing by the prime minister's comments.
A spokeswoman insisted he was referring to "already published material" in the
interim report by the ISG.
In the interview with the British Forces Broadcasting Service, Mr Blair had said: "The Iraq Survey Group has already found massive evidence of a huge system of clandestine laboratories, workings by scientists, plans to develop long range ballistic missiles.
"Now, frankly, these things weren't being developed unless they were developed for a purpose."
Echoing what Mr Bremer said, Dr Blix said that the ISG had failed to produce any concrete evidence that the laboratories they had found were working on WMD.
However, Mr Bremer rejected Dr Blix's claim that
there were no WMD left for Saddam to give up.
"You might conclude that Dr Blix is out of touch," he said.
Liberal Democrat foreign affairs spokesman Menzies Campbell said that he would
be pressing ministers on the state of the government's knowledge about Iraqi WMD
when Parliament returns in the New Year.
"It is high time the prime minister cleared this matter up once and for
all," he said.
"Just exactly what was the British Government's state of knowledge at the
time of military action about the presence of weapons of mass destruction and
the facilities for manufacturing them; and what do they know now?"