Britain's Olympic relay silver medallist suspended after positive test, Canada earned bronze in the event

British sprinter CJ Ujah, who was part of the team which won a silver medal in the men’s 4.100-metre relay event, has been provisionally suspended by the Athletic’s Integrity Unit (AIU) after testing positive for a banned substance.

source https://www.cbc.ca/sports/olympics/summer/trackandfield/chinjindu-ujah-tests-positive-4-100m-tokyo-olympics-1.6138959?cmp=rss