Australia’s first heavyweight boxing world titleholder Lucas Browne says he is not a drug cheat but accepts he may be banned after testing positive to clenbuterol.

The 36-year-old nicknamed Big Daddy, who is undefeated as a professional, was tested the same week he made history last month by stopping local hero Ruslan Chagaev in the 10th round in war-ravaged Chechnya.

Browne told reporters on Wednesday he was shocked, disappointed and could not speculate on how he could have tested positive for the banned drug.

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His team say privately they fear food contamination may have taken place in Chechnya as they were under armed guard throughout their stay in Grozny and ordered not to leave their accommodation without a bodyguard for safety reasons.

Plans are in place to have Browne’s B sample analysed by the Las Vegas-based Voluntary Anti-Doping Association (VADA) and he is hopeful the matter can be resolved.

He says while he avoided drinking local water it was not feasible for him to bring in his own food as he was in the country for 12 days.

Positive sample … Lucas Browne. Photo: AAP: World Boxing Association

Browne says he will do everything to clear his name, but the decision was out of his hands.

Meanwhile, he will keep training for his next fight.

“I have no idea about the ‘cleared’ aspect of it … I am confident where I stand, I am completely innocent and the team and everyone else has the right intentions with everything that’s going,” Browne said in Perth.

“Unfortunately social media runs wild with things like this. A lot of people I thought were friends are now jumping on the bandwagon, saying I’m a cheat and everything else when they don’t really know the story.

“I would like to assure all my fans, the whole of the boxing world and all of Australia that I am not a drug user or a drug cheat.”

Clenbuterol is commonly used as a performance enhancing drug to build muscle because it boosts metabolism and burns fat, with athletes caught including cyclist Alberto Contador, sprinter Katrin Krabbe and AFL players Lachlan Keeffe and Josh Thomas.

Browne argues a heavyweight boxer would not use a weight-stripping drug.

He also says his team organised themselves for two VADA tests several days before the fight and after because they did not want to use the local Russian testers.

“We outsourced it ourselves so again it would be completely stupid for me to take something knowing we’re going to be tested … it doesn’t make sense,” he said.

Browne’s promoter British boxing great Ricky Hatton has thrown his support behind Browne, saying he has no doubt the Sydney-born former bouncer is not a drug cheat.

-AAP