Kenichi Ogawa failed a doping test prior to his winning the then-vacant IBF super featherweight title in December, his gym announced Friday.
Although his post-fight tests came back negative, the Nevada State Athletic Commission announced Thursday, according to ESPN, that both samples of Ogawa's pre-fight tests returned positive for two forms of androstanediol.
Ogawa, who defeated Tevin Farmer on Dec. 9 by decision in Las Vegas, is entitled to a hearing within one month.
"One cannot deny that the tests were positive," Ogawa said in a statement released by Teiken Gym. "But I never intentionally took a banned substance. We will cooperate fully so the cause can be discovered."
If Ogawa is found guilty, he could receive a suspension and a fine.
However, a source close to the matter said there is a possibility that a medication for Ogawa's skin condition may have triggered the positive result. He has handed over the medication in question to the NSAC. If it is accepted as a treatment for a medical condition, it is possible that he may escape disciplinary action.
Ogawa's results were negative when he took a doping test in July for the World Boxing Council.