Former heavyweight champion Joseph Parker's failed drug test, which led to a suspension, was reportedly caused by his nutritionist's cocaine use, according to UK Anti-Doping (UKAD). Parker tested positive for benzoylecgonine, a cocaine metabolite, after his fight against Fabio Wardley on October 25.

Parker has consistently denied using prohibited substances. UKAD has now lifted his suspension, allowing him to return to boxing. The investigation revealed Parker's explanation that his nutritionist, a regular cocaine user, had exposed him to the substance. The nutritionist admitted to daily cocaine use in the week leading up to the fight.

A scientific expert concluded that Parker's ingestion of cocaine most likely occurred out of competition, unrelated to sporting performance. Consequently, UKAD proposed a three-month ineligibility period, which has been deemed served. The result of Parker's bout against Wardley has been overturned to a defeat by disqualification.