Greek hurdler Fani Halkia could face a two-year jail sentence after a Greek prosecutor charged the former Olympic champion with using banned steroids.
Greek sprinters Tassos Gousis and Dimitris Regas were charged with using the same steroid, methyltrienolone.
Halkia's coach, George Panagiotopoulos, was charged with supplying banned substances and, if convicted, faces up to three years in prison and a fine.
The defendants deny any wrongdoing and will go on trial within a year.
Halkia, the 2004 Olympic women's 400m hurdles champion, was expelled from the Olympics after testing positive just days before she was due to compete in Beijing.
Her 'B' sample came back positive for methyltrienolone, which the International Olympic Committee (IOC) said is a dangerous drug that "may lead to serious consequences to the health of athletes, even threatening their lives".
In August, the IOC rejected Halkia's defence that she had never used the steroid and that her sample had been subject to "acts of tampering by third parties".
Halkia was a relative unknown before winning gold in Athens, where she set a new Olympic record of 52.77 seconds in the semi-finals.
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