
The two Britons had been due to meet at London’s O2 Arena on Aug 12 in a rematch of their 2015 bout, won by Joshua, at the same venue.
Matchroom said in a statement that the Voluntary Anti-Doping Association had informed them and the sanctioning bodies that Whyte “returned adverse analytical findings as part of a random anti-doping protocol.”
“In light of this news, the fight will be cancelled, and a full investigation will be conducted.”
Whyte lost a title challenge to WBC world champion Tyson Fury in April 2022. Joshua lost his WBA, WBO, IBF, and IBO belts to Ukraine’s Oleksandr Usyk in September 2021.
The outcome of the Joshua versus Whyte fight could have put either fighter in the frame for a lucrative clash with former WBC champion Deontay Wilder.