Donald Rumsfeld, the former US defence secretary, denied on Wednesday that the Pentagon covered up the circumstances surrounding the friendly-fire death in Afghan­istan of Patrick Tillman, a former American football player.

Tillman became a national hero in 2002 after he abandoned a lucrative career with the Arizona Cardinals to enlist as an army Ranger with his brother Kevin. Mr Rumsfeld praised him in a personal letter, saying he was doing a “proud and patriotic thing”.