In a report to air on Sunday's '60 Minutes,' a Lance Armstrong teammate says he witnessed the seven-time Tour de France champ use EPO, an illicit performance-boosting drug.

"I saw it in his refrigerator," Tyler Hamilton tells journalist Scott Pelley. "I saw him inject it, more than one time."

The 39-year-old cancer survivor has always denied steroid use, but the allegations remain under federal investigation.

Hamilton claims knowledge of Armstrong's doping as far back as 1999, the first year the beloved racer won the Tour de France. Other cyclists have shared similar testimony with investigators.

Now Armstrong has come out swinging, enlisting a Bill Clinton strategist to launch a new website, Facts4Lance.com, which disputes the charge that performance enhancers contributed to the athlete's astounding winning streak.