Rep. Henry Waxman asked the White House and Defense Department officials to hand over any communications relating to the death of former professional football star Pat Tillman in Afghanistan.

Waxman, D-Calif., sent Defense Secretary Robert Gates and White House counsel Fred Fielding letters on Friday requesting documents that show how and when officials learned of the circumstances around Tillman's death.

U.S. military officers first reported that Tillman was killed in an ambush but later revealed he was killed by friendly fire.

President Bush said earlier this week that he hopes someone is held responsible for the mishandling of information about Tillman's death.

Tillman's death received worldwide attention because he had walked away from a huge contract with the NFL's Arizona Cardinals to enlist in the Army after the Sept. 11, 2001, terrorist attacks. His family initially was misled by the Pentagon about how he died on April 22, 2004, and did not learn the truth for more than a month.

FOX News' Molly Hooper and The Associated Press contributed to this report.