Disgraced Chinese swimming star Sun Yang has lodged an appeal against his eight-year doping ban with the Swiss Federal Tribunal.
Sun, who also served a three-month doping suspension in 2014, was found guilty of refusing to give a doping sample and banned for eight years by the Court of Arbitration for Sport in February, upholding an appeal by the World Anti-Doping Agency against swimming's governing body Fina.
Unless he is successful with the appeal, Sun will not be eligible for the Tokyo Games in 2021 and his career would be effectively over.
The tribunal did not confirm the information, but according to a report, "a case file has been opened with a number attached to the 'Sun Yang Case'."
Sun, 28, remains suspended from competition during the appeal.
The three-time Olympic champion has previously seen two appeals rejected by the tribunal before the CAS decision.
A vial of Sun's own blood sample was smashed with a hammer during a testing session in 2018, but the swimmer was acquitted by Fina of anti-doping violations. But the ruling outraged Wada, which took the matter to the CAS.
