Alberto Contador

Recently, 2007 Tour de France winner, Aleberto Contador was handed a two-year ban for testing positive for clenbuterol. The Spaniard had initially won the 2010 edition of the famous race as well, but was stripped of his title almost immediately after his transgressions came to light. 

Contador claimed that the excess clenbuterol resulted from food contamination, and that he had no intentions of using the substance for gaining ground on his competitors. Well, that's what they all say when they get caught!