BEIJING (AP) — Kamila Valieva, the 15-year-old Russian superstar who was expected to deliver her nation its third straight Olympic gold medal in women's figure skating, practiced as usual on Thursday, hours after reports surfaced that she had tested positive for a banned substance.

Valieva tested positive for the heart medication before the Beijing Games, the Russian newspaper RBC reported. 

The sample was reportedly obtained before Valieva won the European championship last month in Estonia, a performance that solidified her status as the leader of Russia's "quad squad" of elite women's figure skaters.

It's unclear if Russia is appealing or fighting the result, though her light-hearted appearance at her regularly scheduled practice implies that the federation isn't accepting any finding that would eliminate her.

"She is not suspended," Russian figure skating federation spokeswoman Olga Ermolina said, offering no further detail.

The International Skating Union, the sport's governing body, said in a statement it "cannot disclose any information about any possible anti-doping rule violation."

Valieva ran through her program and skated with teammate Alexandra Trusova while getting pointers from coach Eteri Tutberidze at the practice rink. Valieva flashed a smile to one of her coaches near the end of the roughly 30-minute session, and none of the skaters took questions from reporters.

When Valieva left the media area, she gave a gesture with a fist in the air. It appeared that she responded to something inaudible that was asked by a journalist speaking to her in Russian.

A positive test could not only cost Russia the gold medal from the team competition but threaten Valieva's chance to win the individual competition. It starts Tuesday and she is the overwhelming favorite to win gold.

The drug detected,  trimetazidine, is a metabolic agent that helps prevent angina attacks and treats vertigo, according to the European Union's medicines agency. It is banned by the World Anti-Doping Agency because it can help endurance and increase blood flow efficiency, both of which could help a figure skater.

The most famous case of trimetazidine in sports doping involved Chinese star swimmer Sun Yang, the three-time Olympic champ who served a three-month ban in 2014. Russian bobsledder Nadezhda Sergeeva also tested positive for it at the 2018 Pyeongchang Olympics; she was disqualified from the two-woman bobsled event and served an eight-month ban.

It is unclear whether Valieva applied for a therapeutic use exemption or has a history of heart problems.

Russian athletes are in Beijing competing as ROC, short for Russian Olympic Committee, after the country was banned because of a massive state-sponsored doping scheme at the 2014 Sochi Olympics.

Kremlin spokesman Dmitry Peskov referred reporters to the International Olympic Committee.

"As always, not knowing the essence, everyone began to yell left and right. We will not join this orderly line of screamers," he said.

The IOC and Switzerland-based International Testing Agency, which oversees the Olympic drug testing program, have declined to comment on the case.

On Thursday, IOC spokesman Mark Adams said it would not be appropriate to talk of an ongoing legal case or "all sorts of speculation that I have also seen overnight." 

The case is more complicated because minors have protection within the World Anti-Doping Code from being identified.

"Obviously everyone has been worried, waiting for a decision," said Morisi Kvitelashvili of Georgia, who trains with Valieva in Moscow and has been in contact with her. "Her condition is good, and it seems like everything is fine."

The uncertainty in Valieva's case contrasts with swift action taken by the ITA against an Iranian skier at the Beijing Games. Hossein Saveh Shemshaki gave a sample Monday that tested positive for an anabolic steroid and was provisionally suspended late Wednesday.

The International Skating Union can also take out athletes with interim bans if they test positive at its events, or in samples it gets before Jan. 27, when the ITA took over the Olympic anti-doping program. The ISU also has not commented.

The first indication of a problem with the results of the three-day team competition — which concluded Monday with Russia winning gold, the U.S. silver and Japan bronze — came when the medal ceremony was postponed indefinitely. 

If the Russian team is disqualified, the U.S. team would be elevated to the gold medal for the first time in the event. Japan would be awarded silver and fourth-place finisher Canada would receive the bronze.

If any athlete and team is disqualified or had results nullified, an appeal is likely, which could further delay the medals presentation. The Court of Arbitration for Sport has set up an office in Beijing to hear urgent cases.

"I think there's a lot of other factors that are being put in play," said American skater Nathan Chen, who won the individual title on Thursday and could now end up with another gold medal. "Whatever ends up being the case will be the case, but I'm still wrapped up in what I was able to do today. Looking forward to hearing what is ultimately decided."

Shoma Uno of Japan, who was third in the individual event and now stands to get a team silver medal, said he wasn't certain of all the facts surrounding Valieva's case but seemed to indicate the very notion of doping troubled him.

"Everybody is giving our best in practice to perform for an event like this," Uno said. "What I think, good or bad, is not a big deal, but doping is something (to which) all athletes pay extra attention."

The longer the uncertainty drags on, the more skaters will finish their competitions and leave the tightly controlled Olympic bubble for home.

"Everyone is doing absolutely everything that the situation can be resolved as soon as possible," Adams said, though he cautioned "as you know, legal issues can sometimes drag on."

Traditional doping is uncommon in figure skating because additional muscle mass is generally a negative. But many skaters have been caught over the years trying to control their weight with diuretics, which are banned for their ability to mask steroid use, and other medications that could give them the slightest edge.

Russian skaters in particular have a history of positive results dating to 2000, when decorated pairs skater Elena Berezhnaya was stripped of a gold medal from the European championships for testing positive for pseudoephedrine. 

In July 2020, Maria Sotskova was dealt a 10-year ban just months after announcing her retirement for allegedly forging a medical certificate to explain a doping violation. Sotskova finished eighth at the 2018 Olympics in Pyeongchang.