Former world champion Parker produced a positive sample as part of a doping test carried out on the day he fought in 11th-round stoppage to UK boxer Ipswich-born Wardley.
Fabio Wardley and the New Zealander participated in a thrilling bout in London on 25 October to decide the next WBO mandatory challenger against reigning heavyweight king Ukrainian champion Usyk.
Joseph Parker had positioned himself as next in line to face Oleksandr Usyk following stringing together an impressive six wins in a row, however placed his mandatory challenger status on the line in London and suffered a stoppage in round eleven.
A standard screening administered to Joseph Parker by the Voluntary Anti-Doping Agency the day of the match returned positive and now leaves the veteran boxer facing a challenge to demonstrate his cleanliness.
The boxer's representatives released an announcement which read: "The agency alerted all required parties about Parker tested positive subsequent to an anti-doping test administered on the fight day. During the ongoing inquiry, no more comments are planned at this time."
Parker was crowned titleholder in 2016 before he lost his WBO belt through a points decision against British star Joshua in Cardiff two years later.
Joseph Parker has been a regular competitor in the UK since then, fighting eight times in total on UK territory and transferring to Ireland for fight camps with highly regarded trainer former champion Lee over the past few years.
Under the tutelage of Lee, Joseph Parker overcame the 2022 setback versus British heavyweight Joyce to achieve multiple wins positioning him at the front of the line to challenge the champion prior to he suffered defeat against Wardley.
After Parker's sample showed a failed test during the Wardley bout, reportedly for cocaine, a probe about the test outcome has been started.
Tech enthusiast and hosting expert with a passion for helping businesses optimize their online presence through robust server solutions.