A second Russian athlete has failed a doping test at the Winter Olympics in Pyeongchang, South Korea.

The Russian Bobsled Federation confirmed that Nadezhda Sergeeva had tested positive for a banned substance, a heart medication that affects metabolism.

Two weeks before the Olympics, Sergeeva was seen wearing a shirt in training that read "I don't do doping."

GANGNEUNG, South Korea — A second Russian athlete has failed a doping test at the Winter Olympics in Pyeongchang, South Korea, a day before the International Olympic Committee's executive board is to decide whether to reinstate Russia for Sunday's closing ceremony.

The president of the Russian Bobsled Federation, Alexander Zubkov, told The Associated Press on Friday that a drug-test sample that Nadezhda Sergeeva gave on Sunday was positive.

Earlier this month, Sergeeva, a bobsled pilot, told the AP that competitors from other countries had warmed to her after she passed IOC vetting for Pyeongchang, which included an examination of her drug-testing history.

"I don't know why, but they've started talking to us more than ever before. I feel it. Maybe it's a sign to them that we're clean," Sergeeva said. "There's a lot of people coming up and saying, 'We're happy you're here.'"

At the time, she was training in a T-shirt with the words "I don't do doping." Sergeeva used to compete in track and field as a heptathlete before switching sports in 2010.

Nadezhda Sergeeva was seen wearing a shirt that read "I don't do doping" just before this year's Winter Olympics. YouTube/Roman Bibishev

The Russian delegation at the Pyeongchang Olympics said in a statement that the substance found was trimetazidine, a medication used for people with angina that is listed by the World Anti-Doping Agency as a banned substance affecting metabolism.

"She confirms she took no such medication, and the team confirms she was not issued any medication," said Zubkov, a former bobsledder who was stripped of two Olympic gold medals for the Russian doping scheme at the 2014 Olympics in Sochi, Russia.

He said that "federation representatives at the Olympics" were starting to prepare a defense.

Zubkov also said a sample Sergeeva had given five days earlier was negative.

"I can tell you that on the 13th it was clean, but on the 18th it gave a positive result for the heart medication," he said.

The IOC said later Friday it had been informed of the positive test by the Russian delegation.

Sergeeva's crew finished 12th in the women's bobsled competition on Wednesday, after she had given the sample that later came back positive.

The Russian team was barred from the Olympics in December for doping at the Sochi Games, but the IOC invited 168 athletes from the country to compete under the Olympic flag.

"This won't win us any extra credit," the Russian delegation leader, Stanislav Pozdnyakov, said in comments reported by Russian media. "Unfortunately, this case speaks to negligence by the athlete. She has let us down."

It is the fourth doping case of this year's Olympics. The Russian curler Alexander Krushelnitsky was stripped of his bronze medal Thursday after testing positive for the banned substance meldonium. The Slovenian hockey player Ziga Jeglic and the Japanese speedskater Kei Saito also left the games after testing positive.

Trimetazidine has been detected in previous doping cases. The Chinese swimmer Sun Yang, an Olympic gold medalist, was barred for three months in 2014 by his country's sports authorities after testing positive for the substance.

Sun said he had been prescribed the drug for a medical condition and hadn't known it was banned. The perceived leniency of that three-month ban led to Sun receiving criticism from swimmers from other countries at the 2016 Olympics in Rio de Janeiro, where he won another gold medal.

Russia's bobsled program has for several years been in the spotlight for drug use.

Zubkov and four other bobsledders were disqualified from the 2014 Games for doping, though the four other bobsledders have been reinstated. Another gold medalist, Dmitry Trunenkov, was barred last year for failing a doping test.