Pyeongchang - A Russian curler who passed rigorous vetting to attend the Pyeongchang Olympics was hit by a drug case on Monday, raising questions over the testing programme and the move to let Russians compete despite systemic doping.
Alexander Krushelnitsky, who won bronze in the mixed doubles curling with his wife Anastasia Bryzgalova, was the subject of a new procedure at the Court of Arbitration for Sport's (CAS) anti-doping division.
The case could have wider repercussions - Olympic officials will decide this week whether to lift a ban on Russia and let them march behind their national flag at the closing ceremony on Sunday.
Krushelnitsky was one of 168 athletes passed as "clean" and allowed to compete as neutrals after a targeted testing programme stretching back over several months.
But it has emerged that he failed his A and B test samples and CAS will now decide if there has been a violation and possible sanctions.
A source close to the matter told AFP the case involves meldonium, which increases endurance and helps recovery. Tennis star Maria Sharapova served a 15-month ban after testing positive for meldonium in 2016.
Russia were banned as a team from the Olympics in December after investigations revealed an extensive doping plot culminating at the Sochi 2014 Winter Games, where the hosts topped the medals table.
Russian curling coach Sergei Belanov earlier dismissed the claims against Krushelnitsky, saying doping would be "no advantage" in curling, a sedate ice sport.
"No benefits. No advantage," said Belanov, women's curling coach for the Olympic Athletes from Russia team, when asked why a curler would want to use performance-enhancing drugs.
"And I don't believe a young man chooses risk or will use the same drug that has been around for two years.
"It's stupid and Alexander is not a stupid man."
Krushelnitsky, 25, and his wife last week picked up bronze in the mixed doubles curling after beating Norway 8-4 in the third-place play-off.
"I would never believe someone on our team would do that," said women's curling captain Victoria Moiseeva, adding: "I can't imagine how he and his wife feel."
The International Olympic Committee (IOC) said there could be "consequences" for Russia - a special panel will meet this week to discuss lifting Russia's suspension before the closing ceremony.
IOC spokesperson Mark Adams, when asked if the Russian flag could still be allowed at the closing ceremony, said the panel will examine whether they have followed the "letter and the spirit of the (December) ruling.
"And if it hasn't been there will obviously be consequences."
He said that the IOC stands by the decision to allow supposedly clean Russian athletes compete in Pyeongchang, saying they were "tested at significant levels more than others".
"We went through a very, very rigorous programme... there was a sense from the IOC that we wanted individual athletes, if we could prove they were clean, to have the chance to participate in the Olympic Games," Adams said.
"I think we would very much stick by that decision that athletes should not be judged as a group but we should find a way to rigorously test them and provide a route for clean athletes to compete."
Russian athletes have won 11 medals so far in Pyeongchang, including the curling bronze as well as silvers in figure skating, cross-country skiing and skeleton.
Russian competitors were subjected to targeted testing under a special taskforce including senior experts and several national anti-doping agencies, Adams said.
"Only athletes for whom there was no suspicion were invited to the Games," he said, adding: "Unfortunately wherever there's competitive sport, you'll have people cheating.
"But I think you can be pretty confident we have a very, very thorough testing process in place and we have the experts with the expertise who are doing that."