A recent drug testing result has officially knocked out the Anthony Joshua-Dillian Whyte rematch.

Matchroom Boxing announced Saturday morning that Whyte was removed from the heavyweight sequel after a random drug test as contracted through Voluntary Anti-Doping Association (VADA) “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.”

The substance in question was not identified as this goes to publication. Representatives from VADA, Matchroom and the British Boxing Board of Control did not immediately respond to a Boxing Scene inquiry seeking further clarification.

The rematch was due to headline an August 12 event from The O2 in London, which also hosted their December 2015 meeting won by Joshua via seventh-round stoppage. The event is still scheduled to move forward with its remaining undercard bouts still intact. Per Chris McKenna of The Daily Star, Joshua’s team has already begun the process to hopefully secure a replacement opponent to remain on the show.

Both fighters were coming off separate twelve-round wins over Jermaine Franklin in their most recent outings. Whyte (29-3, 19KOs) barely outpointed the American heavyweight in a majority decision victory last November 26 at OVO Arena Wembley. Joshua scored a more convincing win over Franklin on April 1, though in a relatively dull affair.

Joshua still has the chance to build on that momentum after back-to-back defeats to Oleksandr Usyk, the first fight which ended his second unified heavyweight title reign.

The future is less certain for Whyte, however.

The former heavyweight title challenger has twice before tested positive for a banned substance. A testing sample collected surrounding his October 2012 knockout win over Sandor Baldogh produced findings of the banned substance Methylhexaneamine (MHA). An investigation by the National Anti-Doping Panel (NADP) acknowledged that it was consumed through an over-the-counter purchase of banned supplement Jack3d but issued a two-year suspension for failure to seek professional or medical advice.

Whyte returned to the ring in October 2014 and won seven in a row to advance to 16-0 before his Dec. 2015 meeting with Joshua. Their entertaining battle resulted in Whyte’s career defeat, which was followed by an eleven-fight win streak. It also included a second drug testing scandal, when it was learned that he tested positive for a banned substance prior to his July 2019 points win over Oscar Rivas.

A subsequent investigation ultimately cleared Whyte, who returned to the ring later that December in a win over Mariusz Wach. The fight was made on short notice and landed on the undercard of Joshua’s unified title-regaining victory over Andy Ruiz, against whom Joshua suffered a seventh-round knockout in his first career defeat six months earlier.

No further update was provided on Whyte’s current drug test, other than a forthcoming investigation.

Three more heavyweight bouts remain in play for the Aug. 12 DAZN-branded event. 

IBF heavyweight mandatory challenger Filip Hrgovic (15-0, 12KOs) and Australia's Demsey McKean (22-0, 14KOs) will meet in a twelve-round battle of unbeaten heavyweights. Faded former title challengers Derek Chisora and Gerald Washington collide in a ten-round bout, while rising prospect Johnny Fisher (9-0, 8KOs) faces Harry Armstrong (5-1-1, 0KOs) in a ten-round regional title fight.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox