Lucas Browne was clean five days before he won Australia's first heavyweight boxing world title.
The 36-year-old from Sydney has produced what he claims is proof he is not a drugs cheat.
Browne sensationally tested positive to banned substance clenbuterol following his WBA regular heavyweight world title fight victory over Russian Ruslan Chagaev in Chechnya earlier this month.
Browne on Wednesday released a statement detailing how his blood and urine were tested by officials from the Las Vegas-based Voluntary Anti-Doping Association (VADA) on February 29 in Chechnya - just five days before his fight on March 6 (AEDT) - and showed no positive results for any banned substance.
"I made it clear to the public last week that I intended to do all that I can to clear my name after the devastating news of the positive drugs test following my successful defeat of Ruslan Chagaev for the WBA Heavyweight World Championship," Browne said.
"I am now able to report to you that on February 29th shortly after arriving in Chechnya I was subjected to a randomly timed drugs test by VADA. This was a test of blood and urine. The post fight test was a urine only test.
"I would like to again stress it was myself and my team who requested the bout be subject to VADA testing.
"I now hold clear and unequivocal evidence that this was a negative test and shows clearly that I arrived in Chechnya a clean athlete. Hatton Promotions have made this information available to the media today.
"Following that clean test I ate only at the hotel in which we were hosted and at the meal following the boxers media weigh in. The water I drank on the night of the fight was sealed bottled water."
Browne said he does not plan to challenge the A sample testing from VADA which showed a positive result for clenbuterol and will not pay the fee needed for VADA to analyse his B sample.
"My team's investigations will now concentrate on the period of time between the clean test on 29 February and the fight itself on March 5," he said.
"I maintain that I did not knowingly consume any banned substance, including the clenbuterol found in my system at that time.
"I will continue to do all that I can to clear my name."
Clenbuterol is predominantly used as a metabolism booster as part of a fat-burning program. The drug increases the average core temperature of the human body, boosting the metabolism of the user.
It comes as IBF, WBO, IBO and WBA (Super) unified world heavyweight champion Tyson Fury hinted that Browne could have been doped against his will in Chechnya.
Fury famously refused to drink water following his win over Wladimir Klitschko in Germany in November fearing it may have been spiked.
He says Browne could have been targeted by people looking to discredit his stunning world title victory.
"Listen, I told you about these waters, didn't I," Fury told iFL TV this week. "What did I say at the Klitschko fight? Someone was trying to hand me drinks of water. I said no. Don't give me nothing.
"Why do you think I wouldn't take a drink until I got home? And I was dying for a drink. I was dehydrated. I could have drunk five gallons of water, but I never because of the drugs situation. Too smart for that lot."