The Court of Arbitration for Sport (CAS) on Friday confirmed a four-year doping ban for U.S. sprinter Erriyon Knighton, rejecting his defense that contaminated beef caused his positive test.
Knighton, 20, tested positive on March 26, 2024, for epitrenbolone, an anabolic steroid, during an out-of-competition test. He was provisionally suspended from April to June 2024.
The Florida-born sprinter was initially cleared by a U.S. tribunal, which accepted the food contamination theory. That ruling allowed him to compete at the Paris Olympics, where he finished fourth in the men’s 200 metres final.
CAS overturned the decision following appeals by the World Anti-Doping Agency (WADA) and World Athletics, which argued that Knighton’s explanations “fell short of the required proof of source and were statistically impossible.”
“There is no proof that would support the conclusion that oxtail imported into the USA would be likely to contain trenbolone residues at the level required,” CAS said in its ruling.
WADA welcomed the decision. “WADA is pleased with the outcome and we will continue to appeal cases to CAS when we feel justice has not been served,” the agency said in a statement.
Knighton’s ban will run from March 26, 2024, to April 12, 2028, with the brief period of provisional suspension deducted.
The sprinter rose to prominence as a teenager, winning bronze at the 2022 World Championships in Eugene and silver at the 2023 edition in Budapest.
He was not selected for the U.S. team for the 2025 World Championships in Tokyo, which begin on Saturday.
The ruling represents a major setback for one of America’s most promising young track athletes, once seen as the heir apparent to Usain Bolt in the 200 metres.
