The top science adviser to Saddam Hussein turned himself over to U.S. forces in Baghdad yesterday, becoming the first associate of the deposed Iraqi president to surrender and providing the Bush administration with a potentially valuable source of information about the status of Iraq's proscribed weapons programs.

Lt. Gen. Amir Saadi, one of 55 people on the U.S. Central Command's list of most-wanted Iraqi government officials, arranged his surrender with the help of Germany's ZDF television network. It filmed him leaving his Baghdad villa with his German wife, Helga, and presenting himself to a U.S. Army warrant officer, who escorted him away.

Saadi, who worked in the Iraqi chemical weapons program in the 1980s and 1990s under Hussein's son-in-law and last year became the main liaison with U.N. weapons inspectors, told the German network that Iraq no longer possessed weapons of mass destruction -- a position he maintained before the war in his contacts with the U.N. inspection teams.

"He would know Iraq's chemical weapons program, since he lived with it," said Hans Blix, the chief U.N. inspector, in a telephone interview yesterday. As late as March 19, the day before the war against Iraq started, Blix said, he received a letter from Saadi saying Iraq had destroyed all its chemical and biological weapons.

"I was telling the truth, always telling the truth, never told anything but the truth, and time will bear me out, you will see," Saadi told ZDF. "There will be no difference after this war."

Three days after the Iraqi government collapsed and after more than three weeks of war, U.S. military and intelligence forces have yet to report any discoveries of banned weapons or weapons systems.

ZDF reported that Saadi also said he did not know where Hussein was, continuing the mystery of whether the former Iraqi leader is alive or dead. Also unknown is the whereabouts of more than four dozen other Iraqi officials on the U.S. list.

A chemist who was educated in Britain and Germany, Saadi was counselor to the presidency for scientific and technical affairs but was never considered part of Hussein's inner political and military circle.

Saadi, according to the German television network, had been in his Baghdad home since U.S. forces arrived in the capital and decided to turn himself in after learning he was on the United States' most-wanted list. In announcing the list Friday, the Central Command said it was distributing decks of playing cards with the names and faces of the 55 Iraqi officials on them.

Saadi was on the seven-of-diamonds card.

His surrender in downtown Baghdad was arranged through his wife with ZDF network representatives in Baghdad. ZDF said one of its camera crews accompanied Saadi to the meeting with the Army officer and filmed his departure in a jeep.

Blix said Saadi was "extremely knowledgeable and businesslike with no trace of propaganda in our discussions." In that sense, Blix added, he was different from Iraqi Deputy Prime Minister Tariq Aziz, who always wanted to inject politics in discussions over weapons inspections.

However, Saadi's statements, that all of Iraq's chemical and biological weapons were destroyed in the summer of 1991, "had no credibility," Blix said. In the days before the war, Saadi argued in a letter to Blix that he could prove Iraq had destroyed unaccounted-for stockpiles of anthrax and VX nerve agents through an analysis of the soil where, he said, they had been dumped.

Saadi also played a major role in the previous U.N. inspections in Iraq in the 1990s. In 1998, when then-chief inspector Richard Butler, head of the U.N. Special Commission (UNSCOM), reported that Iraq was interfering with his operations, Saadi led the Iraqi government's attack on the inspectors. He told reporters that Butler "is just exerting maximum pressure and provoking and beating the drums of war. He is just acting like a U.S. or a British politician."

Saadi said then that "the facts are Iraq declared these weapons. Iraq presented these weapons to UNSCOM, and Iraq destroyed them under the supervision of UNSCOM." One major problem in the inspections that resumed in November and ended shortly before the war, Blix said, is that, in contrast to what Saadi said five years ago, Iraq claimed it had destroyed its biological and some of its chemical weapons "unilaterally" without UNSCOM being present and had no records to prove the destruction.

In January, when the United States was attempting to interview Iraqi scientists outside the country, Saadi told ABC News that he had been approached by U.S. and British agents during his trips abroad and asked to defect. He told reporters he never thought of defecting, and U.S. intelligence sources said he was not asked to do so.

Secretary of State Colin L. Powell, in his presentation of the U.S. case against Baghdad to the U.N. Security Council on Feb. 5, said Saadi belonged to a high-level commission headed by Iraq's vice president, Taha Yassin Ramadan, and included Hussein's son Qusay. The commission reported directly to the Iraqi leader and managed the inspections that Powell said included movements of weapons to deceive the U.N. group.

"It was General Saadi who last fall publicly pledged that Iraq was prepared to cooperate unconditionally with inspectors," Powell said. "Quite the contrary. Saadi's job is not to cooperate; it is to deceive; not to disarm, but to undermine the inspectors; not to support them, but to frustrate them and to make sure they learn nothing."

A day after Powell's speech, Saadi told reporters in Baghdad that the satellite pictures of alleged missile and chemical sites presented to the Security Council by Powell were "cartoons" and that the reports from defectors were "unreliable." He accused Washington of undermining the inspection program, saying, "What we heard today was for the general public and mainly the uninformed to influence their opinion and to initiate aggression on Iraq."

In this video image, Saddam Hussein's scientific adviser, Amir Saadi, left, is driven away in a U.S. military vehicle in Baghdad.Lt. Gen. Amir Saadi is one of 55 people on the U.S. Central Command's wanted list to be displayed on decks of playing cards. Saadi was the seven of diamonds.Amir Saadi has insisted that Iraq destroyed all of its chemical and biological weapons, telling German TV: "I was telling the truth, always telling the truth, never told anything but the truth, and time will bear me out."