United States sprinter Erriyon Knighton has been banned from athletics for four years after the Court of Arbitration for Sport (Cas) upheld appeals from World Athletics and the World Anti-Doping Agency.
The ban, which is effective immediately, comes after the 21-year-old tested positive for the banned substance trenbolone in March 2024.
Knighton, who finished fourth in the 200m at the Paris Olympics last summer, had previously been cleared by an independent arbitrator after claiming his positive test was due to meat contamination.
However, Cas has now ruled against this, stating that there was “no proof” to support the claim that contaminated meat would have caused the high levels of the substance found in his system.
The ruling means Knighton will not compete in the World Championships in Tokyo, Japan, which begin on September 13.
In related news, Ethiopian middle-distance runner Diribe Welteji, a 1500m silver medalist at the 2023 World Championships, will also miss the upcoming World Championships after a provisional suspension was upheld while her doping case is heard.
She was charged with failing or refusing to submit a doping sample.
