Greek Olympics sprinter Tassos Gousis failed a doping test on Friday, the day of the grand opening ceremony of the Beijing Olympics, state television said, dpa reported.
It's the latest doping scandal to rock Greece. The 29-year-old sprinter was scheduled to compete in the 200-metres event in Beijing.
The Greek athlete tested positive, following tests conducted by the Greek anti-doping agency ESKAN, while the team was training in Japan.
Officials said the first sample examined contained the same substance, methyltrienlone, as the 11 weightlifters and swimmer Yiannis Drymonalos caught earlier this year.
Gousis is reportedly set to return to Greece immediately.
The Hellenic Olympic Committee refused to comment before the results of the athlete's second test are released.