In an emotional appearance in front of the television cameras, Alberto Contador on Tuesday vowed to return to cycling after serving the remainder of a two-year ban imposed upon him by the Court of Arbitration for Sport (CAS) after a positive test for clenbuterol at the 2010 Tour.

"I am going to continue fully in cycling," the Madrid-born racer said. "I will continue to compete cleanly, as I have done all my life." Describing the past year-and-a-half since the positive test became known as "a nightmare," Contador declined to comment on whether his sanction was the result of a witch hunt.

"I don't want to go into that," he said. "Anybody who has read the resolution knows clearly that I did not dope."

Asked whether he would appeal the CAS' decision, which concluded that he had most likely ingested the banned substance via a contaminated food supplement, Contador said he "would fight to the end," and that his lawyers would study all avenues.