Ukrainian cross-country skier Marina Lisogor has failed a drugs test at the Sochi Winter Olympics, it has been confirmed.
The International Olympic Committee's Disciplinary Commission announced that the 30-year-old tested positive for the substance trimetazidine.
A Ukrainian Olympic Committee statement read: "The International Olympic Committee's disciplinary commission officially informed the Ukrainian NOC today that Ukrainian cross country skier Marina Lisogor was tested positive for the substance trimetazidine included in the forbidden substances list since January 1, 2014.
"Marina Lisogor gave her explanation at the disciplinary commission meeting that she took the drug product 'Preductal' not knowing that it consists the forbidden ingredient, thus unintentionally breaking the IOC anti-doping rules. The decision regarding Maryna Lisogor will be made in accordance with IOC regulations."
The Ukrainian is the third athlete to fail a drugs test in Sochi, following positive results for Evi Sachenbacher-Stehle of Germany and William Frullani of Italy.