Anthony Joshua’s scheduled rematch against Dillian Whyte has been cancelled after the latter "returned adverse analytical findings" from a random anti-doping test.
The Voluntary Anti-Doping Association said it had informed the Association of Boxing Commissions and the British Boxing Board of Control that a "random anti-doping protocol" undertaken by Whyte had returned the adverse findings, leading to the bout being called off and an investigation being launched.
The fight had been due to take place at London’s O2 Arena on Saturday, 12 August.
Fight promoter Matchroom said in a statement: "Today, the Voluntary Anti-Doping Association (VADA) informed Matchroom, the Association of Boxing Commissions and the British Boxing Board of Control that Dillian Whyte had 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 said he was "devastated" to learn of the report and protested his innocence.
"I am shocked and devastated to learn of a report by VADA of adverse findings relating to me," he said in a statement on Twitter.
"I only learned of it this morning and am still reacting to it.
"I have also just seen that the fight is being cancelled without having any chance to demonstrate my innocence before the decision was taken.
"I can confirm without a shadow of doubt that I have not taken the reported substance, in this camp or at any point in my life.
"I am completely innocent and ask to be given the time to go through the process of proving this without anybody jumping to conclusions or a trial by media."
Whyte says he has produced false positive tests in the past and will fight the result of this one.
"I insisted on 24/7 VADA testing for this fight, as I have done voluntarily and at my own expense for all of my fights for many, many years," he added.
"This is not the first time that I have been reported as having an adverse finding for a substance which I have not taken, and as I did last time I will again prove that I am completely innocent.
"In the meantime all I can do is express my extreme disappointment to boxing fans, who will miss out on what was sure to be a great event."
