At Los Angeles in 1984, 12 athletes tested positive for drug use.

Through the first 10 days of competition here, seven athletes have tested positive, including the two Bulgarians who won gold medals in weight lifting.

For the next 16 days, 10,000 athletes from 172 nations will test themselves and each other in the first boycott-free Games in 20 years.

More than 1,100 athletes in 1988 tested positive for banned substances, a majority of them anabolic steroids.

There, 16 athletes from 10 nations tested positive for banned drugs.

Not one Chinese athlete has tested positive for drugs at the Athens Games.

Only one athlete has tested positive, Exum said, which made him question the effectiveness of catching cheaters.

And during the Olympic trials, it was revealed that three athletes had tested positive for banned substances before competition began.

His athlete tested positive; and because of it, her medal was withdrawn.

At those Olympics, seven athletes tested positive for performance-enhancing drugs, including five cross-country skiers.