Alexander Krushelnitsky, a bronze-medalist along with his wife in mixed-doubles curling, is suspected of having tested positive for the drug.
Reports emerged on Sunday alleging that a member of the Olympic Athletes from Russian Federation team (OAR) had failed a doping test, although the International Olympic Committee (IOC) refrained from identifying any competitor in a statement that stressed it would be "extremely disappointing" if a case is proven. A spokesman for the Russian delegation at Pyeongchang said he had no immediate comment. It was offered to Russian national teams in numerous sports, and was believed to help athletes tolerate tough training workloads. If it's confirmed, the bronze medal in curling will go to Norway.
Alexander Krushelnytsky's failed a preliminary doping test, putting his medal, and Russia's efforts to move past revelations of state-sponsored doping, behind it.
The Russians had been hoping that a clean record at Pyeongchang would persuade the International Olympic Committee (IOC) to allow them to march at the closing ceremony on February 25 with the Russian flag and in national uniform.
The IOC have been criticised for opening the door for athletes to take part at Pyeongchang 2018, despite the country's doping scandal.
Several Russian media outlets are reporting the OAR team has been notified of a "possible violation of the anti-doping rules" by the International Olympic Committee (IOC), but are waiting on the results of a B sample to confirm the breach. The Court for Arbitration in Sport announced last week that Japanese short-track speedskater Kei Saito tested positive for high levels of acetazolamide, a diuretic that can be used as a masking agent.
The IOC said in a statement: "On the one hand it is extremely disappointing when prohibited substances might have been used, but on the other hand it shows the effectiveness of the anti-doping system at the Games".