Russia on Tuesday confirmed that curler Alexander Krushelnitsky had tested positive for the banned substance meldonium at the Pyeongchang Olympics.

“The (B) sample gave a positive result, confirming the presence of a banned substance in the body,” the Russian Olympic Committee said in a statement. “We deeply regret this incident.”

Russia, however, insisted that the concentration of meldonium found in Krushelnitsky’s sample was “absolutely insignificant from the point of view of any sort of therapeutic effect on the human body.” The ROC also said that Krushelnitsky’s previous tests had come back negative.

Meldonium was added to the World Anti-Doping Agency’s list of banned substances in 2016. Russian tennis player Sharapova, a former world No 1, served a 15-month ban after testing positive for meldonium early that year.

The International Olympic Committee had suspended Russia in December after revelations of a widespread and highly orchestrated doping conspiracy, which first emerged before the Rio 2016 Summer Games. As many as 168 athletes from the country are competing in Pyeongchang as neutral Olympic Athletes from Russia.

The IOC was considering lifting the ban before the Pyeongchang closing ceremony on February 26. However, it isn’t yet clear how this development would affect that decision. The Court of Arbitration for Sport had said on Monday that it had opened an anti-doping case against Krushelnitsky.

With inputs from AFP