Alexander Povetkin has been implicated in a second doping controversy of the year ©Getty Images

Russian boxer Alexander Povetkin has denied deliberately doping after a world title fight was abandoned following a failed drugs test for banned muscle booster ostarine.

It marked the second doping controversy of the year for the 37-year-old following a failure for meldonium in April.

Povetkin, an Olympic champion at Athens 2004, had been due to fight Canadian Bermane Stiverne for the vacant interim World Boxing Council (WBC) heavyweight title yesterday.

But the WBC withdrew their recognition of the fight and launched an investigation after the failure.

The Russian instead fought France’s Johann Duhaupas in a non-title fight in Yekaterinburg.

"What sense does it make to use doping and fail the last test?" Povetkin told Russia's official news agency TASS after knocking-out his opponent in the sixth round.

"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."

The WBC decision was announced on Twitter by the body's President Mauricio Sulaiman.

Ostarine was added to the World Anti-Doping Agency (WADA) Prohibited List in 2008 as a designer steroid described as a selective androgen receptor modulators (SARM).

It is thought to be particularly beneficial building up muscle mass during training periods.

Romanian-Canadian boxer Lucian Bute also failed for the substance earlier this year.

Alexander Povetkin ultimately fought a bout for which no titles were at stake ©Getty Images
Alexander Povetkin ultimately fought a bout for which no titles were at stake ©Getty Images

Povetkin escaped a WBC ban in April, despite failing for the banned heart attack drug meldonium.

The produce was banned by WADA on January 1, but they subsequently admitted that "more research" was required to assess how long traces of the substance could remain in the human body.

A scheduled fight against United States' Deontay Wilder was cancelled as a result of the first failure.