Nadezhda Sergeeva, who finished 12th in the two-woman bobsleigh, has become the second Russian athlete to test positive for a banned substance at the Winter Olympic Games in PyeongChang.
Nadezhda Sergeeva, 30, is one of 168 Russians allowed to compete as neutrals at the Games despite the country being banned for previous doping offences.
She finished outside of the top ten in the two-woman bobsleigh event.
On Thursday, Russian curler Alexander Krushelnitsky was stripped of his bronze medal after being found guilty of doping.
The Russian Bobsleigh Federation said Sergeeva had tested positive for "a heart drug" that "was not prescribed" by its medical team. Sergeeva tested positive for trimetazidine, a stimulant usually used to treat patients suffering from angina.
It added that a test on 18 February came back positive but a previous one on 13 February had showed a clean result.
The news, just 24 hours after Krushelnitsky backdoor exit from the Olympic Games, is a major blow for the International Olympic Committee, who will meet on Saturday to decide whether the Russian team will be allowed to march under their own flag at Sunday’s closing ceremony.