Sunday 15 May 2016 21:16, UK
The WBC has confirmed next Saturday's heavyweight clash between Deontay Wilder and Alexander Povetkin has been postponed.
American Wilder (36-0-KO35) was due to head to Moscow on Monday for the final preparations for the fourth defence of his belt but his Russian opponent failed a drugs test.
Povetkin's sample tested positive for meldonium, a substance that was added to the World Anti-Doping Authority (WADA) banned list last year and caused tennis star Maria Sharapova to be banned.
Promoter Andrei Ryabinsky confirmed Povetkin had been taking meldonium before it was banned and that only "leftover traces of meldonium at a very low concentration" were found in a blood sample given last month.
But the WBC has decided the bout is off, pending an investigation, with no back-up date.
"Keeping the priority of safety and also the principle of justice, the WBC will continue the investigation into the case," the WBC said in a statement.
"Consequently, the event scheduled for May 21 in Moscow is hereby officially postponed."
Wilder later said in a statement: "I'm very disappointed that due to Povetkin's failed drug test the fight is not going to happen on May 21 in Moscow
"I had worked very hard to prepare myself for this important title defence, spending the last two weeks training in England to get accustomed to fighting in Europe. I wanted to give the fans a great show, but we understand the WBC's position that the fight occur on an even playing field.'
"This is a huge disappointment and a setback to my goals in boxing. I want to be an active heavyweight champion and it is still my goal to collect all the belts and become the undisputed heavyweight champion of the world."
