The German intelligence officials responsible for one of the most important informants on Saddam Hussein's suspected weapons of mass destruction say the Bush administration and the CIA repeatedly exaggerated the man's claims during the run-up to the Iraq war.

Five senior officials from Germany's Federal Intelligence Service said in interviews with the Los Angeles Times that they warned U.S. intelligence authorities that the source, an Iraqi defector code-named Curveball, never claimed he had produced germ weapons and never saw anyone else do so.

According to the Germans, President Bush mischaracterized Curveball's information when he warned before the war that Iraq had at least seven mobile factories brewing biological poisons. Then-Secretary of State Colin L. Powell also misstated Curveball's claims in his prewar presentation to the United Nations on Feb. 5, 2003, the Germans said.

Curveball's German handlers have said for the last six years that his information was often vague, mostly secondhand and impossible to confirm.

"This was not substantial evidence," a senior German intelligence official said. "We made clear we could not verify the things he said."

The German authorities, speaking about the case for the first time, also said that their informant suffered from emotional and mental problems. "He is not a stable, psychologically stable guy," said an intelligence official who supervised the case.

Curveball was the chief source of inaccurate prewar U.S. claims that Iraq had a biological weapons arsenal, a commission appointed by Bush reported earlier this year. U.S. investigators did not interview Curveball, who still insists his story is true, or the German officials who handle his case.

The German account emerges as Washington is engaged in a political battle over prewar intelligence. The White House lashed out last week at Senate Democrats and other critics who allege that the administration manipulated intelligence to go to war. Democrats have prompted the Senate Intelligence Committee to resume a long-stalled inquiry. Democrats in the House are calling for a similar inquiry.

An inquiry by the Los Angeles Times based on interviews since May with about 30 current and former intelligence officials in the United States, Germany, Britain and Iraq, and at the United Nations, shows that U.S. bungling in the Curveball case was far worse than official reports have disclosed.

The White House, for example, ignored evidence that U.N. weapons inspectors disproved virtually all of Curveball's accounts before the war. Bush and his aides issued increasingly dire warnings about Iraq's germ weapons as the invasion neared, even though intelligence from Curveball had not changed.

At the CIA, senior officials embraced Curveball's claims even though they could not verify them or interview him until a year after the invasion. They ignored multiple warnings about his reliability, punished in-house critics who provided proof that he had lied and refused to admit error until May 2004, 14 months after the invasion.

After the CIA vouched for Curveball's information, Bush warned in his State of the Union address in January 2003 that Iraq had "mobile biological weapons labs" designed to produce "germ warfare agents." The next month, Bush said in a radio address and a statement that Iraq had "at least seven mobile factories" for germ warfare.

Curveball told his German handlers, however, that he had assembled equipment on only one truck and had heard secondhand about other sites. Moreover, he could not identify what the equipment was designed to produce.

"His information to us was very vague," the senior German intelligence official said. "He could not say if these things functioned, if they worked."

Powell also highlighted Curveball's "eyewitness" account when he warned the U.N. Security Council on the eve of war that Iraq's trucks could brew enough weapons-grade microbes "in a single month to kill thousands upon thousands of people."

The German intelligence supervisor said he was aghast when he heard Powell misstate Curveball's information as a justification for war.

"We were shocked," the German official said. "We had always told them it was not proven."

In a telephone interview, Powell said then-CIA Director George J. Tenet and his top deputies personally assured him before the Feb. 5, 2003, speech that intelligence on the mobile labs was "solid." Since then, Powell said, the case "has totally blown up in our faces."

Powell said no one warned him that veterans in the CIA's clandestine division, including the European division chief, had voiced growing doubts to supervisors about Curveball's credibility.

At the United Nations, Powell said the eyewitness was at the site of a 1998 weapons accident that had killed 12 technicians. Lawrence B. Wilkerson, then Powell's chief of staff, said CIA leaders had explained that the "principal source had not only worked in the mobile labs, but had seen an accident and had been injured in the accident."

But German intelligence officials say the CIA was wrong. Curveball had "only heard rumors of an accident," the intelligence supervisor said.

Tenet has denied ignoring warnings that Curveball might be a fabricator. He declined to be interviewed for this report.

Curveball also could not be interviewed. German officials threatened last summer to strip him of his salary, housing and protection if he agreed to meet the Times. Curveball now lives under an assumed name in southern Germany.

Germany opposed the Iraq invasion, but German intelligence authorities insisted they shared everything they gleaned from Iraqi informants.

CIA officials now concede that Curveball fused fact, Internet research and what former co-workers called "water cooler gossip" into a nightmarish fantasy that played on U.S. fears after the Sept. 11, 2001, attacks. His motive, they say, was to get a German visa, not start a war.

After the invasion, the CIA's Iraq Survey Group found that Curveball was fired from his job in 1995, at the time he said he was starting work on germ weapons.

A former CIA official said records showed he had been jailed for an apparent sex crime and that for some time he drove a Baghdad taxi. His childhood friends called him a "great liar" and a "con artist."

British intelligence warned the CIA in 2001 that spy satellite images taken four years earlier, when Curveball claimed to be working at a grain-handling facility he said was used as a mobile germ factory at Djerf al Nadaf, conflicted with his descriptions. The photos showed a wall around most of the main warehouse, clearly blocking trucks from entering.

U.N. weapons inspectors were the first to disprove Curveball's claims. On Feb. 8, three days after Powell's speech, members of U.N. Team Bravo left their Baghdad hotel to conduct the first search of Curveball's former work site.

Behind a high wall, a two-story grain silo adjoined a tin-roofed warehouse -- the building Curveball had identified as the truck assembly facility.

The doors were locked. So Rocco Casagrande, a Boston microbiologist, crawled through a hole in the wall. He scraped five samples from the walls and floor and tested them that day for bacterial or viral DNA. The results were all negative.

A British inspector found another surprise. Curveball had said the germ trucks could enter the warehouse from either end. But there were no doors. And a six-foot-high wall surrounded most of the building. It was the wall British intelligence had seen in 1997 satellite photos. It clearly prohibited the traffic flow Curveball had described.

The U.N. inspectors "could find nothing to corroborate Curveball's reporting," the CIA's Iraq Survey Group reported last October, more than a year after the invasion.

U.N. teams also raided the other sites Curveball had named and found no evidence of germ trucks or anything suspicious. On March 7, 2003, Hans Blix, the chief U.N. weapons inspector, told the Security Council that searches had found "no evidence" of mobile biological production facilities in Iraq.

The invasion of Iraq began two weeks later.