Former world heavyweight boxing champion Joseph Parker has taken to social media to address his “surprise” after failing a drug test.

It came after the 33-year-old failed a drugs test on October 25 – the same day of his shock loss to Fabio Wardley in London.

“The Voluntary Anti-Doping Association last night informed all parties that Joseph Parker returned an adverse finding following an anti-doping test conducted on the 25th of October in relation to his bout with Fabio Wardley,” Queensberry Promotions said today.

In a statement on Instagram, Parker said: “Before my recent flight I took a voluntary test and have now been informed that it returned an adverse result. This came as a real surprise to me.”

He continued: “I did not take any prohibited substance, I do not use performance enhancing drugs and do not support their use.

Parker said he was “cooperating fully with the process now underway”.

“And I am confident the investigation will clear my name.”

He thanked supporters who had reached out with messages of encouragement.

“When the investigation is complete, I will speak openly and answer questions.”

Parker, who has a record of 36-4 with 24 KOs, faces a potential lengthy ban by the British Boxing Board of Control, which did not immediately respond to a request for comment.

The WBO also has not yet responded.