Heavyweight contender Alexander Povetkin failed his second drug test in seven months, forcing his vacant interim world title fight against former world titleholder Bermane Stiverne to be canceled about 20 hours before they were to walk to the ring.
Povetkin and Stiverne were due to meet on Saturday at the Ekaterinburg Expo Center in Ekaterinburg, Russia, Povetkin's home country.
However, the fight was canceled when the WBC withdrew its sanction of the bout because Povetkin tested positive for the banned substance ostarine in a random Voluntary Anti-Doping Association drug test conducted under the WBC's Clean Boxing Program, which allows for random testing at any time.
Povetkin provided the sample on Dec. 6 and VADA notified the fighters and organization of the failed test on Saturday.
"The WBC hereby withdraws its sanctioning of the bout for the heavyweight interim world championship and will conduct a thorough investigation of the circumstances of the case and will issue subsequent rulings as required," the WBC wrote in its ruling.
Ostarine, which is supposed to increase stamina and recovery ability, has been on the World Anti-Doping Agency banned list since 2008.
Povetkin promoter Andrey Ryabinsky of World of Boxing said of the positive test on social media that Povetkin was "not clear where it came from."
Stiverne (25-2-1, 21 KOs) could have gone through with the bout but without the sanction and a chance to win the interim title he elected not to.
"There's no reason to fight if the WBC won't sanction the bout," Stiverne said. "I'm very disappointed in the actions of Povetkin. I've been training for months to be victorious. To wake up the day of the fight, have breakfast, take a nap and wake up to find out he tested positive is the worst possible situation."
World of Boxing announced that Johann Duhaupas (34-3, 21 KOs), 35, of France, would step in and face Povetkin in the new main event. Duhaupas has won two fights in a row, including a six-round knockout of Robert Helenius on April 2, since WBC titleholder Deontay Wilder knocked him out in the 11th round of a title defense September 2015.
Apparently, Duhaupas was already in Russia and took the fight on less than a day's notice, although it is unclear how the fight was set up so quickly and why Russian regulators are allowing Povetkin to fight in the wake of the failed test.
Stiverne, 38, who was born in Haiti and lives in Las Vegas, made immediate plans to leave Russia.
"I'm headed back home to Las Vegas," he said. "Hopefully, the WBC will install me as the mandatory challenger to face Deontay Wilder. I want the opportunity to fight for the world title again, that was my whole reason to come to Russia was to earn that opportunity."
Stiverne, who is promoted by Don King, lost a lopsided decision and the title to Wilder in January 2015 in Las Vegas. However, with Wilder sidelined after having surgery this past summer because of a hand and biceps injury, the WBC sanctioned the interim title bout.
The cancelation of the fight will cost both fighters their purses of $1,424,250 apiece. Another $316,500 would have gone to the winner of the fight, which Ryabinsky won at a purse bid.
It is Povetkin's second canceled fight because he tested positive for a banned substance this year. He was the mandatory challenger and due face Wilder on May 21 in Moscow. The fight was canceled nine days beforehand, when Povetkin (30-1, 22 KOs), 37, failed a VADA test for the banned substance meldonium, which he claimed he ingested before the drug was added to the WADA banned list in January.
The WBC ultimately elected to not punish Povetkin because the amount of the substance in his system was far below the threshold accepted by WADA in an updated notice on the drug published in June. There remain questions, however, about how Povetkin could have tested negative in random VADA doping tests conducted April 7, 8 and 11 while his April 27 sample -- the A and the B -- was positive for meldonium.
Povetkin's latest failed test came a month after Stiverne failed a random drug test for the banned substance methylhexaneamine, a stimulant also known as dimethyamylamine or DMAA. The WBC fined Stiverne $75,000 but ruled that he would still be allowed to fight. The WBC said Stiverne was "cooperative and 100 percent forthcoming" during its investigation.
"Stiverne informed the WBC that on the day of the test, in order to facilitate urination, he took a dietary supplement called Superharm in front of the sample collector," the WBC said at the time. "He reported the ingestion of that supplement in the declaration of medication use section of the doping control form he filled in connection with the test."