Hungary's top sprinter Gabor Dobos is the latest sportsman to test positive for raised levels of testosterone.
Dobos's career could be ended by his drugs test failure
The Hungarian Athletics Association said if his B sample is also positive, Dobos, 30, will get a life ban after a two-year drugs suspension in 2000.
He has been withdrawn from this month's European Championships in Sweden along with Hungary's 4x100m relay team.
Olympic 100m champion Justin Gatlin and Tour de France winner Floyd Landis have also recorded high testosterone levels.
Both men are awaiting the results of tests on their B samples, with Landis expected to discover his on Saturday.
The male sex hormone helps recovery after exercise and increases energy and strength.