Jarrell Miller, who was denied a license by New York boxing officials over a failed test on Wednesday, has failed a second drugs test, the US media reported yesterday.
Miller recently tested positive for human growth hormone (HGH) which is on the World Anti-Doping Agency banned list.
Miller’s planned June 1 fight against world heavyweight champ Anthony Joshua had already been scuppered by the first failed drug test which came to light on Tuesday.
“Salita Promotions and Greg Cohen Promotions are very disappointed in these findings and feel awful fight fans will be deprived of what would have been a great fight,” Dmitriy Salita and Greg Cohen, Miller’s co-promoters, told American sports broadcaster ESPN.
“It’s a terrible outcome and unfortunate situation for all parties involved.”
Miller, who is undefeated in his 24 professional fights, was due to take on the Briton at Madison Square Garden for the WBA, IBF and WBO titles.
Miller previously served a nine-month ban from the California State Athletic Commission after testing positive for methylhexaneamine when kickboxing in 2014.
Joshua still plans to make his US debut as planned in June for what will be his seventh title defense.
Promoter Eddie Hearn said he was scrambling to find an alternative opponent.
“To be honest I can’t believe it. You always want to give an athlete the benefit of the doubt, but this leaves no doubt,” Hearn told ESPN.
Meanwhile, his promoter, Sarah Fina of Greg Cohen Promotions, as said that his fighter is a victim of African-American status.
The promoter said treatment of Miller differed to that suffered by other fighters.
Miller has apologised after an “adverse finding” saw his June fight against Britain’s Anthony Joshua called off.
Then after a second adverse finding was reported on Friday, the 30-year-old American admitted he had “messed up”.
Some critics have since responded by saying Miller should now be banned for life.
“Firstly, I do not condone cheating whatsoever,” Fina posted on social media.
“Am I upset and disappointed with Jarrell? Absolutely. What Jarrell has done is wrong 100%. But what I won’t do is turn my back on him. People make bad choices in life.
“With all of that being said, it is hard for me not to think that he is being nailed to the cross because he is an African-American fighter.”
She pointed out Mexican fighter Saul ‘Canelo’ Alvarez recently signed a $365m (£280m) multi-fight deal with streaming broadcaster DAZN, despite a six-month ban for failing two drug tests. He claimed to have eaten tainted meat.
“Even the very fighter that was asked to replace Miller, Luis Ortiz, tested for banned substances,” Fina added.
Cuban Ortiz has been linked with taking Miller’s place, though a replacement will not be named until next week.
The 40-year-old tested positive for banned substances in 2017 but avoided a ban because boxing chiefs found he took the drugs for high blood pressure.
Fina said she she had also suffered abuse over the issue for being Miller’s promoter.
“I can’t help but to think that a lot of that has to do with the fact that I am a woman in a male-dominated industry. This is not me playing the victim, but stating facts,” she added.