SAN FRANCISCO -- Olympic gold-medal winner Antonio Pettigrew admitted for the first time Thursday that he took performance-enhancing substances during a long, successful track and field career in which he passed all drugs tests.

The admission came during testimony in the trial of Trevor Graham. Pettigrew's former coach is accused of lying to federal authorities investigating doping in sports. He has pleaded not guilty. Pettigrew testified that in 1997 Graham encouraged him to inject human growth hormone and the oxygen-boosting drug EPO, both of which are banned in track. Soon after, Pettigrew said he began buying the drugs from Angel "Memo" Heredia, an admitted steroids dealer from Laredo, Texas.