ASHINGTON, June 8 — Two of the highest-ranking leaders of Al Qaeda in American custody have told the C.I.A. in separate interrogations that the terrorist organization did not work jointly with the Iraqi government of Saddam Hussein, according to several intelligence officials.
Abu Zubaydah, a Qaeda planner and recruiter until his capture in March 2002, told his questioners last year that the idea of working with Mr. Hussein's government had been discussed among Qaeda leaders, but that Osama bin Laden had rejected such proposals, according to an official who has read the Central Intelligence Agency's classified report on the interrogation.
In his debriefing, Mr. Zubaydah said Mr. bin Laden had vetoed the idea because he did not want to be beholden to Mr. Hussein, the official said.
Separately, Khalid Sheikh Mohammed, the Qaeda chief of operations until his capture on March 1 in Pakistan, has also told interrogators that the group did not work with Mr. Hussein, officials said.
The Bush administration has not made these statements public, though it frequently highlighted intelligence reports that supported its assertions of links between Iraq and Al Qaeda as it made its case for war against Iraq.
Since the war ended, and because the administration has yet to uncover evidence of prohibited weapons in Iraq, the quality of American intelligence has come under scrutiny amid contentions that the administration selectively disclosed only those intelligence reports that supported its case for war.
Bill Harlow, a spokesman for the Central Intelligence Agency, declined to comment on what the two Qaeda leaders had told their questioners. A senior intelligence official played down the significance of their debriefings, explaining that everything Qaeda detainees say must be regarded with great skepticism.
Other intelligence and military officials added that evidence of possible links between Mr. Hussein's government and Al Qaeda had been discovered — both before the war and since — and that American forces were searching Iraq for more in Iraq.
Still, no conclusive evidence of joint terrorist operations by Iraq and Al Qaeda has been found, several intelligence officials acknowledged, nor have ties been discovered between Baghdad and the Sept. 11, 2001, attacks on Washington and New York.
Between the time of the attacks and the start of the war in Iraq in March, senior Bush administration officials spoke frequently about intelligence on two fronts — the possibility of links between Iraq and Al Qaeda, and Baghdad's drive to develop prohibited weapons. President Bush described the war against Iraq as part of the larger war on terrorism, and argued that the possibility that Mr. Hussein might hand over illicit weapons to terrorists posed a threat to the United States.
Several officials said Mr. Zubaydah's debriefing report was circulated by the C.I.A. within the American intelligence community last year, but his statements were not included in public discussions by administration officials about the evidence concerning Iraq-Qaeda ties.
Those officials said the statements by Mr. Zubaydah and Mr. Mohammed were examples of the type of intelligence reports that ran counter to the administration's public case.
"I remember reading the Abu Zubaydah debriefing last year, while the administration was talking about all of these other reports, and thinking that they were only putting out what they wanted," one official said.
Spokesmen at the White House, the State Department and the Pentagon declined to comment on why Mr. Zubaydah's debriefing report was not publicly disclosed by the administration last year.
In recent weeks, the director of central intelligence, George J. Tenet, and other officials have defended the information and analysis by the C.I.A. and other intelligence agencies in the months before the war. They said reports were not suppressed, and were properly handled and distributed among the intelligence agencies.
The issue of the public presentation of the evidence is different from whether the intelligence itself was valid, and some officials said they believed that the former might ultimately prove to be more significant, since the Bush administration relied heavily on the release of intelligence reports to build its case, both with the American people and abroad.
"This gets to the serious question of to what extent did they try to align the facts with the conclusions that they wanted," an intelligence official said. "Things pointing in one direction were given a lot of weight, and other things were discounted."