WASHINGTON — A "very damning" report by the Defense Department's inspector general depicts a Pentagon that purposely manipulated intelligence in an effort to link Saddam Hussein to al-Qaida in the run-up to the U.S. invasion of Iraq, says the chairman of the Senate Armed Services Committee.

"That was the argument that was used to make the sale to the American people about the need to go to war," said Sen. Carl Levin, D-Mich. He said the Pentagon's work, "which was wrong, which was distorted, which was inappropriate ... is something which is highly disturbing."

The investigation by acting inspector general Thomas F. Gimble found that prewar intelligence work at the Pentagon, including a contention that the CIA had underplayed the likelihood of an al-Qaida connection, was inappropriate but not illegal. The report was to be presented to Levin's panel at a hearing today.

The report found that former Pentagon policy chief Douglas J. Feith had not engaged in illegal activities through the creation of special offices to review intelligence. Some Democrats also have contended that Feith misled Congress about the basis of the administration's assertions on the threat posed by Iraq, but the Pentagon investigation did not support that. Two people familiar with the findings discussed the main points and some details Thursday on condition they not be identified.

Levin has asserted that President Bush took the country to war in Iraq based in part on intelligence assessments — some shaped by Feith's office — that were off base and did not fully reflect the views of the intelligence community.

In a telephone interview Thursday, Levin said the IG report is "very damning" and shows a Pentagon policy shop trying to shape intelligence to prove a link between al-Qaida and Saddam.

Levin in September 2005 had asked the inspector general to determine whether Feith's offices' activities were appropriate, and if not, what remedies should be pursued.

The 2004 report from the Sept. 11 commission found no evidence of a collaborative relationship between Saddam and Osama bin Laden's al-Qaida terror organization before the U.S. invasion.

Asked to comment on the IG's findings, Feith said in a telephone interview that he had not seen the report but was pleased to hear that it concluded his office's activities were neither illegal nor unauthorized. He took strong issue, however, with the IG's finding that some activities had been "inappropriate."

"The policy office has been smeared for years by allegations that its pre-Iraq-war work was somehow 'unlawful' or 'unauthorized' and that some information it gave to congressional committees was deceptive or misleading," Feith said.

Feith called "bizarre" the inspector general's conclusion that some intelligence activities by the Office of Special Plans, which was created while Feith served as the undersecretary of defense for policy — the top policy position under Defense Secretary Donald Rumsfeld — were inappropriate but not unauthorized.

"Clearly, the inspector general's office was willing to challenge the policy office and even stretch some points to be able to criticize it," Feith said, adding that he felt this amounted to subjective "quibbling" by the IG.

Feith left his Pentagon post in August 2005 and now teaches at Georgetown University's School of Foreign Service.