A brutal blow for heavyweight boxer Joseph Parker following his defeat by Fabio Wardley in London last month

It's been reported that Parker failed a drugs test on the day of his loss, with news outlets in the United Kingdom saying the former world champion tested positive for cocaine.

In a statement, the New Zealander's promoter Queensberry, said Parker returned "an adverse finding following an anti-doping test", but there's no reference to the substance in question.

Parker could face a ban from the sport depending on the outcome of the investigation.