Sochi, Feb 22 (IANS): The International Olympic Committee (IOC) Saturday confirmed the first doping case of the Winter Olympics as German biathlete Evi Sachenbacher-Stehle tested positive for a stimulant.

Two-time Olympic champion Sachenbacher-Stehle, 33, tested positive Feb 17 for methylhexaneamine, the IOC said in an announcement. The IOC then disqualified her fourth place finish from both the women's 12.5 km mass start and the mixed relay event, reports Xinhua.

The athlete has left the Olympic village and the German team's chef de mission Michael Vesper said an investigation is going on.

"The prosecutor's office was involved in the process yesterday and it is absolutely necessary that all the details of this case are carefully considered," he said.

"We are all aware of the doping control rules and our athlete wanted to emphasise that it was not her intention to use this prohibited medicine. She was not aware she was taking a prohibited medical treatment and was not aware she was under threat of positive doping results."

The IOC planned to carry out the most stringent Olympic doping control programme between Jan 30 and Feb 23. Within that period, the IOC systematically performed tests before and after events. After each event, the IOC systematically carried out tests on the top-5 finishers plus two at random.

IOC also performs out-of-competition unannounced tests. Over the course of the Sochi Games, the IOC is expected to carry out some 2,453 tests including 1,944 urine and 509 blood.