Sun Yang

The ban is backdated to 28 February, 2020 and means the swimmer will miss this summer's Olympics in Tokyo.

A new Cas panel held the latest hearing after a Swiss Federal Tribunal ruling.

The 29-year-old missed a doping test in September 2018 and was given an eight-year ban for his second offence.

He was first cleared of wrongdoing by Fina, the swimming federation, in January 2019.

But after an appeal by the World Anti-Doping Agency (Wada) to Cas that decision was overturned.

Sun was banned for eight years by CAS in February after it accepted an appeal from WADA against a decision by swimming body FINA to clear Sun of wrongdoing for his conduct during a 2018 test.

Sun appealed against that decision and WADA has issued a statement sayng they have been informed the Swiss Federal Tribunal had upheld a challenge but not made any comment on the substance of the case.

"WADA will take steps to present its case robustly again when the matter returns to the CAS Panel, which will be chaired by a different president," the statement said.