The International Olympic Committee will appeal to Switzerland's supreme court against rulings which cleared some Russian athletes of doping at the Sochi Games.

IOC spokesman Mark Adams says it is "unsatisfied both by the decision and the motivation" of verdicts by Court of Arbitration for Sport.

The Swiss Federal Tribunal can overturn CAS verdicts if legal process was abused, though appeals rarely succeed.

Days before the Pyeongchang Olympics opened in February, two CAS judging panels upheld appeals of 28 Russian athletes against IOC sanctions. CAS said while the evidence did not prove doping offences, it did not mean the 28 were declared innocent of taking part in orchestrated cheating.

A further 11 Russians lost their appeals at CAS, which confirmed disqualifications from the 2014 Sochi Olympics.