Jolanda Ceplak, the 800m indoor world record holder, has been suspended after testing positive for EPO.
Ceplak's case will be heard by the Slovenian athletics federation
The 30-year-old Slovenian failed an out-of-competition test in Monaco on 18 June, and the result has been confirmed by her 'B' sample.
"I deny any connection with taking illegal substances," said Ceplak. "I will try to prove my innocence by all possible means."
Ceplak must now await a hearing by the Slovenian athletics federation.
If found guilty of using the blood-boosting drug EPO, Ceplak faces a two-year ban and would miss the 2008 Olympics in Beijing.
Ceplak won bronze at the 2004 Athens Games and gold in the 2002 European Championships, and had been training in Porec, Croatia, ahead of Slovenia's national championships on Saturday.