Olympic 100m hurdles champion Brianna McNeal will miss the Tokyo Games starting later this month, as well as Paris 2024 after her appeal against a five-year doping ban was dismissed.
The 29-year-old American was suspended by the Athletics Integrity Unit in April after a disciplinary tribunal found her guilty of “tampering within the results management process”.
The Court of Arbitration for Sport (Cas) “partially upheld” the decision.
Her ban runs until August 2025.
McNeal, who won gold at the 2016 Rio Games and was world champion in 2013, was provisionally suspended in February.
At the time she said in a social media post at the time that she was “very clean, very honest and transparent”.
It is the second time the athlete has been banned for breaching anti-doping rules, having missed the 2017 World Championships while serving a one-year ban for missing three drug tests.
Tampering or attempted tampering with any part of doping control carries a ban of up to four years if proved, though McNeal could have faced a ban of up to eight years as it was her second breach.
McNeal has also had all her competitive results from 13 February and 14 August las year disqualified.