Moscow, Dec 24 (IANS): The doping sample taken from Russian heavyweight boxer Alexander Povetkin on December 13 has not revealed traces of banned substances, his promoter Andrei Ryabinsky said.

"We have just received the results of Povetkin's new doping sample taken by the Voluntary Anti-Doping Association on December 13. He is clean, no doping has been detected," Ryabinsky wrote on his Twitter account on Friday.

"Is that what they call honest American sport. We are probing into this case."

On Saturday, December 17, Povetkin beat France's Johann Duhaupas. The non-title 10-round fight held in the Russian Urals city of Yekaterinburg ended with Povetkin's win by a sixth round knockout, reports Tass.

Povetkin was also to meet Canada's Bermane Stiverne for the interim World Boxing Council (WBC) heavyweight title but the fight was cancelled after the 37-year-old's probe A proved to be positive of containing Ostarine. The probe is dated December 6.

The WBC said that a probe into Povetkin's case is ongoing and he can be disqualified.

Ostarine is a SARM substance, which athletes use during training. It builds up endurance, like anabolic steroids. The World Anti-Doping Agency (WADA) put SARM substances on its prohibited items list in 2008.