Tyson Gay's Olympic gold medal - tarnished today. Testing positive for a banned substance.
The Lafayette high grad, owner of the US record in the 100 meters, pulling out of the world championships.
Gay telling the Associated Press that's he awaiting his "b" sample and will not participate in the Moscow competition.
Gay saying: "I don't have a sabotage story. I basically put my trust in someone and i was let down."
We'll have more as the story develops...