Russian bobsledder fails doping test for meldonium

MOSCOW -- Russian bobsledder Nadezhda Sergeeva says she has tested positive for meldonium.

Sergeeva, who raced at the 2014 Sochi Olympics, tells Russian agency R-Sport that she tested positive last month.

She adds that she last took the substance in "late 2015" and used it "strictly in connection with cardiological problems which had become apparent."

Meldonium, which boosts blood flow, has been banned since Jan. 1, prompting a number of doping cases across a range of sports. Last week, Maria Sharapova admitted that she tested positive for meldonium at the Australian Open.

Also Thursday, the Russian swimming federation said world champion Yulia Efimova was provisionally suspended but did not comment on reports that it was because of meldonium.