PYEONGCHANG, South Korea -- The Court of Arbitration for Sport has confirmed that Russian curling medalist Alexander Krushelnitsky has been charged with a doping offense at the Pyeongchang Olympics.
The court said Monday that it has "initiated a procedure" involving Krushelnitsky, who won bronze in the mixed doubles event along with his wife, Anastasia Bryzgalova. The court says no hearing date has been set.
IOC spokesman Mark Adams said a failed doping test by a Russian athlete could keep the country's banned team from being reinstated and marching under the national flag at the closing ceremony.
Krushelnitsky's "A sample" tested positive for meldonium, which was banned in 2016. Adams said results of a second sample would be tested, and results could be announced within 24 hours.
The Norwegian mixed doubles curling team finished fourth and could get the bronze if the positive test is confirmed.
Krushelnitsky was not with the curling team at the arena on Monday.
Russian Curling Federation president Dmitry Svishchev told The Associated Press that Krushelnitsky tested clean as recently as Jan. 22, the day before he flew to a pre-Olympic training camp in Japan.
Svishchev said it was possible that an athlete's food or drink had been spiked with meldonium and suggested that rival Russian athletes or Russia's political enemies could be responsible.
"It can't happen at the Olympic Village because everyone eats the same canteen food," he said. "It could happen at training camp or in the intervening period ... There's a possibility of it being something within the team, that something happened during training camp or as a political means to achieve some goal."
The curling team trained in Japan in January, bringing in Russian athletes who had not qualified for the Olympics as training partners.
This is the second doping case of the Pyeongchang Olympics, after a Japanese short-track speedskater tested positive for a banned diuretic.
Meldonium is the substance that tennis star Maria Sharapova was suspended for after she tested positive at the 2016 Australian Open. Before it was banned, many Russian athletes used the drug, which is designed for people with heart problems.
Russian athletes are participating in the Pyeongchang Olympics as "Olympic Athletes from Russia." The IOC suspended the Russian Olympic committee last year in connection with a massive doping scheme at the 2014 Olympics in Sochi but allowed 168 athletes to compete under neutral uniforms and without the Russian national flag.
Adams said Russians at the games have undergone "rigorous testing" and added that "Russians were tested to a significant level more than others."
The case was the talk of the rink at curling.
Although to the uninitiated the idea of a curler using performance-enhancing drugs might seem bizarre, the sport demands a high level of athleticism at the Olympic level. Curlers need to have strong core muscles and upper-body strength to manage the often rigorous sweeping that helps them guide the rock down the ice.
Fitness is even more important in mixed doubles, the event in which Krushelnitsky was competing. Because there are just two curlers on each mixed doubles team instead of the four in traditional curling, there is little rest between throws, and both teammates are often heavily involved in sweeping.
"It's physically demanding out there. It's not like you don't need any muscles," said Swiss curler Silvana Tirinzoni, whose team beat the Russian women's team 11-2 in Monday's round robin. "We have to be fit, and we have to be working out. My sweepers are working out like five times a week, go to the gym, so it [performance-enhancing drugs] can help, but we shouldn't do that. I think that's stupid."
Tirinzoni said that if the reports are confirmed, they would be disappointing. But she said she had no reservations about playing against the Russian athletes on Monday.
"I think clean athletes have the right to compete," she said. "It's not about me to make those kind of decisions. So I believe the team we played today, they are as clean as we are."
According to statistics recently published by RUSADA, the Russian Anti-Doping Agency, Krushelnitckii and Bryzgalovoy were tested only once apiece in 2017. That number does not include tests that might have been done by the World Curling Federation, which does not release testing data, or a multinational pre-Games testing task force.
The Russian delegation and World Curling declined to comment when reached by ESPN.
The IOC announced its suspension of the Russian Olympic Committee in early December and created a vetting process to decide which athletes, support staff and officials to "invite" to compete in Pyeongchang. Included in that announcement was a proviso that the suspension could be lifted by the start of the closing ceremony, provided that the delegation abided by rules of conduct.
All members of the "Olympic Athlete from Russia" team were required to sign an "integrity declaration" promising to adhere to anti-doping rules that apply to all athletes -- an extra layer of paperwork imposed because the IOC was the entity that invited them, as opposed to their national Olympic committee. The IOC also wrote conduct guidelines concerning apparel and use and display of the Russian flag, which athletes were permitted to have in their rooms at the Olympic village but not elsewhere. Russian fans, however, have not been stopped from displaying the flag and colors.
Nicole Hoevertsz of Aruba, chairwoman of the IOC panel that developed those guidelines, said at the Feb. 6 full IOC session that criteria for lifting the suspension was "a little bit open and flexible,'' and "individual incidents" will not necessarily result in the suspension being continued. The IOC leadership has never explicitly stated whether one or multiple doping violations would factor into the decision.
The only other doping case so far at the Pyeongchang Olympics came when Japanese short-track speedskater Kai Saito tested positive for a banned diuretic and was removed from competition. His case is ongoing.
Information from The Associated Press and ESPN's Bonnie D. Ford and Tom Hamilton was used in this report.