Five-time world champion Pavel Kulizhnikov is one of three Russian speed skaters who have tested positive for the banned drug Meldonium, the International Skating Union (ISU) said.

The B samples of Olympic short track gold medalist Semion Elistratov and 2015 European short track champion Ekaterina Konstantinova also tested positive.

Meldonium was added to the World Anti-Doping Agency's list of banned substances on January 1.

Kulizhnikov, 21, served a ­suspension for doping violations between 2012 and 2014 and a second positive test could leave him facing a life ban.