American and British intelligence analysts with direct access to the evidence are disputing claims that the mysterious trailers found in Iraq were for making deadly germs. In interviews over the last week, they said the mobile units were more likely intended for other purposes and charged that the evaluation process had been damaged by a rush to judgment.

"Everyone has wanted to find the 'smoking gun' so much that they may have wanted to have reached this conclusion," said one intelligence expert who has seen the trailers and, like some others, spoke on condition that he not be identified. He added, "I am very upset with the process."

The Bush administration has said the two trailers, which allied forces found in Iraq in April and May, are evidence that Saddam Hussein was hiding a program for biological warfare. In a white paper last week, it publicly detailed its case, even while conceding discrepancies in the evidence and a lack of hard proof.

Now, intelligence analysts stationed in the Middle East, as well as in the United States and Britain, are disclosing serious doubts about the administration's conclusions in what appears to be a bitter debate within the intelligence community. Skeptics said their initial judgments of a weapon application for the trailers had faltered as new evidence came to light.