Why was Floyd Landis stripped off his 2006 victory in Tour de France?

Explanation

Floyd Landis (born 1975)is an American former cyclist. He was crowned the winner of Tour de France 2006 on Champs d'Elysees. A doping test after the 17th stage showed a testosteron level more than double of what is allowed. The analysis also showed that it was artificial testosteron. With that, Landis lost his victory. It is part of the story that Landis had a meltdown on the 16th stage, but then went on to win the 17th stage with an impressive solo run.