Tyler Hamilton - Former professional cyclist
For years, it's been one of the biggest questions in sport.
Did Lance Armstrong - the seven time winner of cycling's greatest race, the Tour de France - dope?
Is the man who beat cancer to become one of the greatest sporting figures ever - a cheat?
Armstrong has denied wrongdoing.
But now a former teammate and roommate of Armstrong's, Tyler Hamilton, has produced the most detailed and wounding set of allegations yet.
Is Hamilton self-serving and greedy, as Armstrong insists?
Or a shaft of light on a sport that's been mired in murk?
(Image: US cyclist Tyler Hamilton. Credit: AFP/Getty Images)