The Russian delegation at the Pyeongchang Olympics has received notification that a Russian athlete has been flagged for a positive performance-enhancing drug test. While the International Olympic Committee hasn’t named the athlete, both The Guardian and Sport Express reported it was curler Alexander Krushelnytsky. Both Krushelnytsky and Anastasia Bryzgalova, who are married, won a bronze medal for mixed curling.

“One of the doping tests of the Russian curler Alexander Krushelnytsky showed suspicious results,” Sport Express reported. “Traces of meldonium, forbidden to WADA from January 1, 2016, are found. Earlier this was reported by Russian journalist Dmitry Derunets.”

Krushelnytsky’s alternate or B-sample is scheduled to be examined Monday. He and Bryzgalova could be stripped of their medal if the B-sample also contains meldonium.

The National Center for Biotechnology Information lists meldonium as a treatment for heart attack victims. Tennis pro Maria Sharipova has been one of the more prominent athletes previously banned for using the substance.

In December of 2017, the IOC formally banned Russia from the 2018 Olympics as punishment for previous doping violations. Per the terms of the ban, Bryzgalova and Krushelnytsky were competing as neutral athletes. The Russian flag and national anthem were not allowed to be on display.

High-ranking members of Russia’s anti-doping agency have gone on record confirming an elaborate plan involving bribes and tampering with athletes’ urine samples that spanned multiple Olympic Games.

“On the one hand it is extremely disappointing when prohibited substances might have been used, but on the other hand it shows the effectiveness of the anti‑doping system at the Games which protects the rights of all the clean athletes,” an IOC statement obtained by The Guardian read.