Former European ice dancing champion Ekaterina Bobrova told Russian media on Monday she failed a doping test, ruling her and her partner Dmitry Soloviev out of the world championships in Boston this month.
Bobrova told Russian agency R-Sport that she tested positive for the heart medication meldonium, which is banned in sport, after finishing third at the European Championships in January.
Bobrova and Soloviev were Olympic gold medallists in the team event in 2014 and won the European title in 2013.
Bobrova said her failed test was "a big shock for all of us" because she had been careful to avoid products containing banned substances and had been specifically warned about meldonium, which became illegal on Jan. 1.
"We always are very strict in tracking what we eat and the medicine we take. At the moment, we're trying hard together with the federation to get to the bottom of this situation."
Skating's world governing body, the ISU, refused to confirm or deny whether Bobrova was suspended, citing medical confidentiality.
Meldonium was used as a popular sports supplement in former Soviet Union countries. Since it was banned, two Ukrainians in the winter sport of biathlon have also tested positive.