Former heavyweight world champion Joseph Parker has publicly addressed a past failed drug test that led to a suspension from professional boxing. According to information released by UK Anti-Doping (UKAD), Parker attributed the presence of a banned substance in his system to secondary exposure. He claimed that his nutritionist had been using cocaine, and that his own positive test resulted from contact with the substance through that individual.

The disclosure provides insight into the circumstances surrounding the suspension, which had previously been a point of scrutiny in Parker's career. While the report confirms Parker’s explanation for the failed test, it highlights the challenges athletes face regarding strict liability rules in anti-doping regulations, where the athlete is generally held responsible for any substance found in their system regardless of how it was ingested. The case serves as a notable example of the complexities involved in doping investigations, where personal associations and environmental factors are often cited as defenses against performance-enhancing drug allegations. The report from UKAD serves as the primary record of this specific defense, though it does not detail the specific disciplinary outcome or the extent to which this explanation was accepted by anti-doping authorities as a mitigating factor.