Yekaterinburg (Russia), Dec 18 (IANS): Russian heavyweight boxer Alexander Povetkin has told reporters that he did not use banned performance enhancing substances and does not know how steroids entered his body.

"What sense does it make to use doping and fail the last test? It is all senseless. I don't know how the substance got into my body. I don't even have any assumptions. When I learnt about it I was getting uneasy. I took it so hard," Povetkin was quoted as saying by Tass.

On Saturday, Povetkin beat France's Johann Duhaupas. The non-title 10 round fight here ended with Povetkin's win by a sixth round knockout.

Povetkin was also to meet Canada's Bermane Stiverne for the interim WBC heavyweight title but the fight was canceled after Povetkin's sample returned positive for Ostarine, a banned substance.

The World Boxing Council 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.