Joseph Parker has pleaded his innocence and denied that he took a prohibited substance in the build-up to his fight with Fabio Wardley last month. 

On Friday, news broke that Parker had tested positive for cocaine on the day of that bout, with his UK manager verifying reports later in the day.  

The former world champion, 33, was tested by VADA (Voluntary Anti-Doping Agency) on October 25 and an adverse finding was subsequently revealed. 

Parker, who lost to Wardley in a major upset, failed the test, with cocaine metabolite benzoylecgonine showing up in the findings. In most cases the B-sample shows up with exactly the same result and VADA will give their findings to the BBBoC (British Boxing Board of Control). 

The governing body will then decide on any potential punishment for Parker, which could end up being a lengthy ban from boxing. 

However, taking to Instagram early on Saturday morning (GMT), the Kiwi fighter expressed his surprise at the news.

His social media post began: 'I want to address today's news.

'Before my recent fight I took a voluntary test and have now been informed that it returned an adverse result. This came as a real surprise to me.

'I did not take any prohibited substance, I do not use performance enhancing drugs and do not support their use.

'I am cooperating fully with the process now underway, and I am confident the investigation will clear my name.

'Thank you to everyone who has sent messages of support. It means a great deal to me and my family.

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

Speaking on Friday, Spencer Brown, who manages Parker in the UK, had given his instant reaction to the bombshell news. 

He said: 'We are in total shock at the findings, we are just waiting to speak to Joe, David Higgins and his promoter Frank Warren. 

'It's very early days and we will get to the bottom of it all.'

Parker's promotional company Queensberry added a statement which read: '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 the 25th October in relation to his bout with Fabio Wardley.

'While the matter is investigated further, no additional comment will be made at this time.'

According to boxing expert Mike Coppinger, Parker could have consumed the drug as little as 48 hours before fight night.

'Cocaine is water soluble - eliminated when one urinates and sweats - and only stays in the system around 48 hours,' he tweeted on Friday. 'Can be longer with heavy use. But casual use usually 48 hours and three days max.'

Meanwhile, the National Drug and Alcohol Screening Association (NDASA) say cocaine can be detected in urine up to four days after consumption. 

Parker is currently on holiday but will have the opportunity to have his B-sample tested.

Even though cocaine is considered a recreational rather than performance-enhancing drug, he could still face years out of the sport. 

Back in 2018, British boxer Liam Cameron was banned for four years after he tested positive for benzoylecgonine, a metabolite of cocaine, though he denied any wrongdoing. 

Parker is a father of six and was with his wife and children during the week of the Wardley fight, which he lost via an 11th-round stoppage.