Canelo Alvarez has pulled out of next month's rematch with Gennady Golovkin.
The Mexican fighter has withdrawn from the bout to challenge two failed two drug tests and the temporary suspension he was handed as a result of them.
Alvarez tested positive for fat-burning substance clenbuterol, but his camp insists that this was a result of eating contaminated meat.
"I am truly shocked by what has happened and I lament that this has caused people to have doubts about my integrity. I have always been a clean fighter," Boxing News quotes the fighter as saying.
Golovkin remains the unified IBF, WBA and WBC middleweight champion following his controversial draw with Alvarez in the original match, and he will reportedly search for a new opponent for to face on May 5 following the news of the Mexican's withdrawal.