The Athletics Integrity Unit has launched an appeal after USA sprinter Erriyon Knighton was cleared over a doping offence allowing him to compete at the Paris 2024 Olympics.

The appeal has been lodged with the Court of Arbitration for Sport (Cas).

Knighton, 20, tested positive for trenbolone – a banned substance used for muscle growth – in March but avoided a ban following an independent arbitrator’s ruling.

The United States Anti-Doping Agency (Usada) said the independent arbitrator ruled he more than likely digested the banned substance by eating contaminated meat.

The 200m world silver medallist went on to compete at the Olympics and finished fourth in the men’s 200m final.

“This appeal is against the decision of an arbitration tribunal in the United States that the athlete established no fault or negligence,” the AIU said on Wednesday.