Lance Armstrong Accused of Doping

The seven-time Tour de France winner and his team are accused of running a doping system to keep their team on top.

On Sunday night's "60 Minutes", former U.S. cycling professional, Tyler Hamilton, claimed that his former teammate and seven-time Tour de France winner, Lance Armstrong, as well as team leaders from Armstrong's U.S. Postal Team, encouraged, promoted, and used performance-enhancing drugs in an effort to win the famed French competition. Hamilton also said Armstrong received a banned blood transfusion, in which teammates give blood that will be transfused into their body later, in 2000. The revelations have caused federal authorities to request more information about the alleged doping system run by the cyclist and his team. Armstrong has long denied he ever used any drugs and has never tested positive.