Legkov was one of 28 Russian athletes implicated in the country's doping scheme who were cleared by the CAS prior to the 2018 Winter Olympic Games in Pyeongchang.

The 35-year-old, who has since retired from the sport, was initially stripped of the Olympic 50 kilometres gold and relay silver medals he won at Sochi 2014 before his results were reinstated because of the CAS ruling.

The IOC said at an Executive Board meeting in May that they would appeal the CAS decision to the Swiss Federal Tribunal after the organisation claimed it was "dissatisfied both by the decision and the motivation".

Legkov's case is the first which the IOC are contesting as the full reasoned decision on his case is one of only two to have been published so far.

The Swiss Federal Tribunal have the power to overturn CAS verdicts if they believe the legal process was abused, although in reality this is very rare.

They did, however, overturn a decision which prevented Peru striker Paolo Guerrero from representing his country at the FIFA World Cup in Russia, allowing him to play in the tournament.

The IOC appeal therefore appears a long shot, but it also has the aim of sending a message that they are determined to do whatever they can to bring Russian doping to account.

Further appeals are likely once other full verdicts are released.

"We can confirm the IOC has appealed the CAS decision on Alexander Legkov to the Swiss Federal Tribunal, as agreed by the IOC Executive Board on 3 May," said IOC Presidential spokesperson Mark Adams.

"The result will be announced by the tribunal once proceedings are concluded."

In the full verdict on Legkov, published in April, the CAS said it was unable to prove any of the "factual allegations" made by the IOC when they stripped Legkov of his medals and disqualified him from the 2014 Winter Olympics.

It also cast doubt on some of the testimony given by former Moscow Laboratory director turned whistleblower Grigory Rodchenkov, who has provided much of the evidence in the Russian doping cases, but also seemed to confirm the presence of a doping scheme in the country beyond any doubt.