Former World Anti-Doping boss Dick Pound admits many other athletes will have suspicions cast at them in the wake of the Nadzeya Ostapchuk failed drugs test.
The Belarussian Olympic shotput champion has tested positive for a banned anabolic agent wand has been stripped of gold with New Zealand's Valerie Adams to be awarded the gold medal.
Pound says there will be other dopers who have won medals in London.
"Unfortunately we've come to the point, because we've allowed doping in sport to get out of control, that anytime you see a superb performance, there's a big question mark that comes up and you say 'I wonder if that was too good to be true'?"
Pound says he looks at Usain Bolt's performance with scepticism.
"When something is so remarkable these days, you look at it and, rightly or wrongly, there's a question in your mind. You can't accuse of him of doping for sure because there's no evidence of it, but if you look at it - is this too good to be true?"
Pound says he doesn't expect a lot more positive drugs tests to come out of the Games.
Photo: Nadzeya Ostapchuk (Getty Images)