Former world 100m champion Tyson Gay has said that he would not have come back to athletics if he had intentionally used performance-enhancing drugs.
The American was banned in 2013 for failing a drugs test, but he has since returned to his best form and won the US Championship last month.
He is quoted as saying by BBC Sport: "When you put key words or a syringe by somebody's name, it manipulates someone's mind to believe you intentionally tried to do something and get away with it.
"That wasn't the case. If I would have made a decision to intentionally do something to hurt the sport I wouldn't have come back."
Gay is the joint second-fastest man in history.