Court of Arbitration for Sport

The court said no hearing date had been fixed yet and no further information would be provided for the moment.

Krushelnitsky, who competes in curling, is suspected of testing positive for meldonium, a banned substance that increases blood flow and improves exercise capacity.

Krushelnitsky, who won bronze with his wife in mixed-doubles curling in Pyeongchang, has not responded to a request for comment.

Russia's curling federation has also launched an "emergency commission" to investigate the doping case, federation president Dmitry Svishchev told Reuters.

The IAAF introduced the rules in 2011 after South Africa’s Caster Semenya had been sidelined for almost a year after winning the world 800 metres title in 2009 as an 18-year-old.

But CAS has issued an interim award in the case brought against the IAAF by India’s 19-year-old sprinter Dutee Chand - who was barred from competing in last year’s Commonwealth Games in Glasgow by the Athletics Federation of India – which maintains the world athletics body has failed to prove that women with naturally high levels of testosterone have a competitive edge.