Ryan Garcia has denied intentionally taking performance-enhancing drugs after his B-sample came back positive for a banned substance.
The 25-year-old intends to use “contamination” from a tainted supplement as part of his defence.
Garcia tested positive for ostarine in two separate tests taken before his fight with Devin Haney on 20 April.
The American beat Haney on points after missing weight for their contest, but the positive tests taken by the Voluntary Anti-Doping Association (Vada) were not revealed until after the fight.
Garcia requested his B-samples be tested and released a statement through his legal team once the same results were confirmed by Haney’s team on Thursday.
They believe “hair samples” will help prove Garcia was the “victim” of “supplement contamination”.
“Ryan Garcia is committed to clean and fair competition and has never intentionally used any banned substance,” Garcia’s legal team said.
“Ryan has voluntarily submitted to tests throughout his career, which have always shown negative results.
“We are certain that one of the natural supplements Ryan was using in the lead up to the fight will prove to be contaminated and are in the process of testing the supplements to determine the exact source.”