Sochi, Russia (SportsNetwork.com) - The Ukrainian Olympic Committee announced on Saturday that cross-country skier Marina Lisogor has failed a doping test, the third positive result of the Sochi Games.

Lisogor tested positive for trimetazidine, although, she says she did not knowingly take the banned substance. She admitted to taking the drug preductal, but said she was unaware that it contained the forbidden ingredient.

The 30-year-old Lisogor competed in two cross country events, but was nowhere near medal contention, as she finished 58th in both the women's free sprint qualification and the 10km classic.

Lisogor's positive result comes on the heels of German biathlete Evi Sachenbacher-Stehle and Italian bobsledder William Frullani both receiving positive tests for banned substances.