Joseph Parker could be facing a two-year ban from boxing after a failed drugs test that showed traces of cocaine discovered in a routine test given to the Voluntary Anti-Doping Agency.
It is understood the date of the test was on the day of the New Zealand heavyweight's fight against Fabio Wardley, which the Briton won last month.
The news of Parker's failed test only emerged on Friday.
- Anthony Joshua and Jake Paul in talks for December fight
- The English champion on his stolen future: 'My life begins now'
- Not got Sky? Get Sky Sports or stream with no contract on NOW
Sky Sports News has contacted Parker's manager, while Frank Warren's Queensbury Promotions released the following statement via their X account.
"The Voluntary Anti-Doping Association [VADA] last night informed all required parties that Joseph Parker returned an adverse finding following an anti-doping test conducted on October 25 in relation to his bout with Fabio Wardley.
"While the matter is investigated further, no additional comment will be made at this time."
The British Boxing Board of Control [BBoC] has told Sky Sports it is "investigating" the matter.
Parker, 33, is a former world champion, who lost his belt to Anthony Joshua in 2018, but he went into his fight against Wardley in arguably the best form of his career.
After a punishing loss to Joe Joyce in 2022, Parker won his last six contests prior to Wardley, picking up victories over Deontay Wilder and Zhilei Zhang among them, as well as winning the WBO Interim strap.
He was due to challenge then IBF belt-holder Daniel Dubois in February, only for Dubois to fall ill just days before the fight was meant to take place.
Parker put his position as the WBO mandatory challenger for undisputed champion Oleksandr Usyk on the line by taking the fight against Wardley.
It was a gamble that backfired and news of his failed drugs test now leaves major questions over the New Zealand heavyweight's future in the sport.
'Possibility Parker is facing a two-year ban'
Sky Sports Boxing expert Andy Scott:
"The headline is shocking.
"Everybody loves Joseph Parker. I think he's most people's second-favourite heavyweight. But there were questions as to why take that fight [against Wardley]?
"He was in line to fight [Oleksandr] Usyk. He instead took a risky fight against Wardley, and now this is the headline.
"Not only did he lose the fight, he now has this investigation that he will have to come out of and clear his name.
"For context, Liam Cameron is the high profile case in boxing with similar circumstances. He received a four-year ban for traces of cocaine, but the rules have changed since then.
"It will be interesting to see how this develops further. There's a full investigation, we'll wait to see what the outcome is of that, but there is a possibility that he's facing a two-year ban."
(c) Sky Sports 2025: Joseph Parker fails drugs test: Heavyweight tested positive for traces of cocaine on day of Fabio Wardley defeat
Grand Slam of Darts: Michael van Gerwen stunned by Danny Noppert after Luke Littler cruises into quarter-finals to set up Josh Rock clash
Grand Slam of Darts 2025: Michael Smith sets up showdown with Luke Humphries after surviving 11 match darts from Chris Dobey
Cristiano Ronaldo sent off in Portugal's loss at Republic of Ireland in 2026 World Cup qualifying
Phil Foden could play as No 9 for England or as Harry Kane's 'accomplice', says Thomas Tuchel
