Australian swimmer Shayna Jack was found guilty of accidental doping on Monday and was given a two-year ban that expires days before the start of the Tokyo Olympics.
The its judges decided “Jack did not intentionally ingest ligandrol and considered that she had discharged her onus of proving that the anti-doping rule violation was not intentional.”
Jack tested positive for the anabolic agent ahead of the 2019 world championships. An Australian sports tribunal previously recommended a four-year ban.
Jack can challenge Monday's ruling in a separate appeal process at CAS. The World Anti-Doping Agency could also appeal to seek a longer ban.
The 22-year-old swimmer, a four-time medalist in relays at the 2017 world championships, cannot compete through July 11, 2021. The Tokyo Olympics open less than two weeks later.
Jack denied doping and said the positive test was caused by a contaminated supplement. The burden of proof is on athletes in anti-doping cases to show exactly how and when any contamination happened.
Jack tested positive in an out-of-competition test in June 2019. The freestyle specialist was suspended from the Australian team and sent home from its pre-worlds training camp in Japan.
At the time, the Australian team said the case was “bitterly disappointing and embarrassing.”