Aug. 1 (Bloomberg) -- Former Defense Secretary Donald Rumsfeld and 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,'' Rumsfeld told the House Oversight and Government Reform Committee at a hearing in Washington today.

The committee is probing how and when top officials at the Pentagon and the White House learned that Tillman's death was probably fratricide. Myers, former chairman of the Joint Chiefs of Staff; retired General John P. Abizaid, former head of U.S. forces in the Middle East, and former Special Operations commander General Bryan Douglas Brown testified today under oath with 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,'' said Representative Henry Waxman, a California Democrat and chairman of the panel.

Army Major General Stanley McChrystal, the top U.S. commander in Afghanistan at the time, warned Abizaid in an April 29, 2004, memo that Tillman may have been killed by fellow U.S. troops.

Abizaid said he received the memo May 6 and immediately telephoned Joint Chiefs chairman 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,'' Abizaid said.

Already Knew

Myers indicated to Abizaid he already knew about the investigation, said 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,'' Abizaid said.

Myers told the committee ``what logically I would have done'' was inform the secretary of defense after 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,'' Myers said.

Tillman, who quit professional football to join the U.S. Army Rangers after the Sept. 11 attacks, died in April 2004 in a friendly fire incident in Afghanistan.

His brother testified to Congress that government officials told ``deliberate and calculated lies'' to conceal that Tillman wasn't slain during a heroic battle against U.S. enemies. Members of his family sat in the back of the hearing room during today's testimony and left with out making any comment.

Democrats Express Doubt

``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,'' Rumsfeld said.

Democrats expressed doubts during the hearing about Rumsfeld's credibility. Republicans said the former secretary of defense answered questions adequately.

Rumsfeld's inability to recall facts about Tillman ``fall a little short,'' Representative Michael Honda, a California Democrat, said after the hearing was over.

Representative Chris Shays, a Connecticut Republican, said Rumsfeld and the generals answered Democrats' questions and he praised Rumsfeld for having ``called their bluff.''

Army's Findings

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.

Geren said there was no intentional cover-up by the Pentagon. Army Vice Chief of Staff Richard Cody said the delay in getting the true story out was because ``everybody wanted to be 100 percent sure so when they told the family they got it right this time.''

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.''

Myers said he didn't ``recall ever having a discussion with anyone in the White House about the Tillman case.''

`Deeply Regrettable'

White House spokesman Tony Snow called the mistakes made in describing Tillman's death ``deeply regrettable.''

``There have been remedial steps taken on the part of the Department of Defense,'' Snow said.

Rumsfeld told the Defense Department's inspector general in December 2006 that he couldn't recall exactly when or how he learned Tillman's death was a fratricide.

``I am told that I received word of this development sometime after May 20, 2004, but my recollection reflects the fact that it occurred well over two years ago,'' Rumsfeld stated in a Dec. 15, 2006, letter to the inspector general.

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

``What doesn't make sense,'' Waxman said, is that while there were hundreds of e-mails among 97 White House officials in the days after Tillman's death, there were none after the Pentagon announced he had been killed by friendly fire.

``One possible explanation is that a series of counter- intuitive, illogical blunders unfolded accidentally and haphazardly,'' Waxman said. ``The other possible explanation is that someone, or some group of officials, acted deliberately and repeatedly to conceal the truth.''

Defense Department Inspector General Thomas Gimble said in a March 26 report that Army commanders recommended Tillman for the Silver Star for gallantry in action, while withholding evidence of friendly fire from his family for five weeks.

To contact the reporter on this story: William Roberts at wroberts@bloomberg.net.

Last Updated: August 1, 2007 15:45 EDT