Traces of cocaine found in a UK Anti-Doping (Ukad) test on heavyweight boxer Joseph Parker were caused by his nutritionist, an investigation has found. Parker, who has always denied knowingly taking banned substances, served a three-month suspension and is now free to fight again.

Ukad's investigation revealed that the nutritionist employed by Parker for his fight against Fabio Wardley was a "regular user of cocaine." The nutritionist admitted to using cocaine daily in the week leading up to the bout on October 25, 2025. Parker provided evidence to Ukad in March 2026, claiming his positive test was a result of exposure to the nutritionist's cocaine use.

Parker was tested by the Voluntary Anti-Doping Association (Vada) on the day of his fight, where he was defeated by Fabio Wardley at London's O2 Arena. He subsequently failed a Ukad test in the early hours of the following day, October 26, 2025.