GENEVA, Dec. 24 (Xinhua) -- The Swiss Federal Supreme Court confirmed on Thursday that it had overturned an earlier decision by the Court of Arbitration for Sport (CAS) to ban Chinese swimmer Sun Yang for eight years due to alleged doping violations.

In a press release, the Swiss Federal Supreme Court said it had approved Sun Yang's appeal for revision of CAS's arbitral award on February 28 on the grounds of bias of one of the arbitrators.

"The award of the CAS is set aside. The CAS will have to render a new award in the case of Sun Yang in a different composition of the panel," said the Swiss Federal Supreme Court.

But the Supreme Court did not give details on the reasoning of its judgment.

In February, the CAS found the three-time Olympic champion guilty of refusing to cooperate with sample collectors during a visit to his Hangzhou home in September 2018 and handed him an eight-year ban.

Sun, who argued that the Doping Control Officer and her assistants lacked sufficient authorization and credentials, then turned to the Swiss Federal Supreme Court, his last court of appeal.