Russian figure skater Kamila Valieva failed a drugs test in December, the International Testing Agency (ITA) has confirmed.

The 15-year-old helped the Russian Olympic Committee to team figure skating gold on Monday at the Winter Olympics. The medals for that event were not awarded due to a "legal issue".

Valieva tested positive for trimetazidine, a medication that is used to prevent angina attacks but is on the World Anti-Doping Agency (WADA) banned list because it improves blood flow to the heart, from a sample taken on Christmas Day during Russia's national championships.

The positive result was confirmed on Tuesday, a day after her team performance in Beijing, leaving her participation for the rest of the Games in doubt.

A provisional suspension was lifted by RUSADA – Russia's Anti-Doping Agency – on February 9, thus allowing her to continue competing in the Chinese capital, on the grounds of what the ITA labelled a "reasoned decision" that has not yet been disclosed.

However, the International Olympic Committee (IOC) and the ITA has appealed against that ruling, and the Court of Arbitration for Sport (CAS) is now set to make a swift ruling on the case, with Valieva's next scheduled appearance due to be in Tuesday's individual event.

The case has been complicated by Valieva's age, as a WADA ruling means competitors under 16 are "protected persons", and athletes concerned remain anonymous.

However, the ITA explained why it decided to make the news public, with a statement reading: "Seeing that some in the media did not grant her the same protection and have reported widely on the basis of unofficial information following the postponement of the medal ceremony of the figure skating Team Event at the Olympic Winter Games Beijing 2022, the ITA acknowledges the necessity for official information due to heightened public interest."

Valieva, who was the first female skater to land a quadruple jump in competition, is the overwhelming favourite for gold in the individual event.