By Vadim Pushkin 

Last Saturday night in Russia, boxing fans watched heavyweight Alexander Povetkin score a knockout victory over France's Johann Duhaupas in six rounds.

Povetkin was originally scheduled to face Canada’s Bermane Stiverne for the interim WBC heavyweight title but the fight was canceled after Povetkin’s drug test from December 6th came back positive for Ostarine. The fight fell apart only a few hours before the event was scheduled to start.

Now it's become known that Povetkin's drug tests from December 13th and December 15th, have come back clean. The test from December 6th had a minor trace of ostarine - [0,00000000001g].

This is the second positive test for Povetkin in the last seven months. He failed a drug test in the lead-up to his scheduled title fight with WBC heavyweight champion Deontay Wilder back in May. That fight was also canceled. The last time he tested positive was for meldonium, which became a banned substance in January of this year. Povetkin admitted to taking the drug last year when it was legal. In that matter, the WBC conducted an investigation and cleared him of any wrongdoing. The WBC has an ongoing investigation on what transpired last Saturday.

Stiverne's trainer, Don House, is not ruling out a rescheduled fight with Povetkin - if the Olympic gold medal winner is clean, and House would prefer to have Povetkin tested on the day of the fight, and learn the result prior to fighting - if that's possible.

"It's a shame that we decided not to fight, because we came to Russia for the title, and then the fight became unauthorized after the results of this test. It was only after a while that they were able to make it clear that he is negative. I would like to have this doping test come up negative on the day of fight," House told Margarita Yakapov.

"I'm just a coach, I little have to do with doping tests, but when we were told that the test was positive, and the WBC in turn immediately refused to sanction the fight, I advised Bermane and his promoter not to do the fight. Unfortunately, we were not able to fight for the title, and now when the [other] test was negative, I just do not know how to respond."

"We are ready to fight with anyone - Povetkin, Wilder, it does not matter who it will be, it's inevitable - but I would like it to be a clean fight on both sides: my side and his opponent. I don't rule out that the opponent will be Povetkin."