A former defense secretary, Donald Rumsfeld, and a retired general, Richard Myers, said they never tried to cover up the news after learning former NFL star and Army Ranger Pat Tillman may have been killed by friendly fire. “I know of no evidence that there has been a cover-up,” Mr. Rumsfeld told the House Oversight and Government Reform Committee at a hearing in Washington yesterday.

The committee is probing how and when top officials at the Pentagon and the White House learned that Tillman’s death was probably fratricide. Mr. Myers, who is a former chairman of the Joint Chiefs of Staff; a retired general, John Abizaid, who is the former head of American forces in the Middle East, and a former Special Operations commander, General Bryan Douglas Brown, testified yesterday under oath with Mr. Rumsfeld.

“We still don’t know who was responsible for the false information and what roles, if any, the Defense Department and White House had in the deceptions,” Rep. Henry Waxman, a Democrat of California and chairman of the panel, said.

Army Major General Stanley McChrystal, the top American commander in Afghanistan at the time, warned Mr. Abizaid in an April 29, 2004, memo that Tillman may have been killed by fellow U.S. troops. Mr. Abizaid said he received the memo May 6 and immediately telephoned Joint Chiefs chairman Mr. Myers.

“I said that it’s clear that there’s a possibility of fratricide involving the Tillman case, that General McChrystal has appointed the necessary people to investigate to determine precisely what happened,” Mr. Abizaid said.

Mr. Myers indicated to Mr. Abizaid he already knew about the investigation, said Mr. Abizaid, whose own headquarters staff had also been aware of it. “They had heard that there was an investigation ongoing within the Joint Special Operations Command,” Mr. Abizaid said.

Mr. Myers told the committee “what logically I would have done” was inform the secretary of defense after Mr. Abizaid’s phone call of the possibility of fratricide in Tillman’s death. “I can’t tell you I did it because I just can’t recall whether I did it or not,” Mr. Myers said. Tillman, who quit professional football to join the U.S. Army Rangers after the September 11, 2001, attacks, died in April 2004 in a friendly fire incident in Afghanistan.

“In no instance was I told that people had the belief that it might have been fratricide and that no one should tell the family,” Mr. Rumsfeld said.

Mr. Rumsfeld’s inability to recall facts about Tillman “fall a little short,” Rep. Michael Honda, a Democrat of California, said after the hearing was over. Rep. Chris Shays, a Republican of Connecticut, said Mr. Rumsfeld and the generals answered Democrats’ questions and he praised Mr. Rumsfeld for having “called their bluff.”

The Army, in a press conference yesterday, laid most of the blame for the handling of Tillman’s death on a retired three-star general.

Army Secretary Peter Geren said Lieutenant General Philip Kensinger, who headed Army special operations, was censured for errors and deceptions, and a review board will consider whether he should be demoted, an action that would reduce his retirement pay.

Mr. Rumsfeld said he didn’t talk to anyone at the White House about the circumstances of Tillman’s death until “it became a matter of public record and the family was notified.” Mr. Myers said he didn’t “recall ever having a discussion with anyone in the White House about the Tillman case.”

White House spokesman Tony Snow called the mistakes made in describing Tillman’s death “deeply regrettable.”

President Bush mentioned Tillman in a May 1, 2004, speech to the White House Correspondents Association annual dinner. Mr. Waxman’s committee is seeking earlier drafts of that speech along with the emails among White House communications staff and speechwriters.