Deontay Wilder added further fuel the fire by claiming he "rehabilitated" Tyson Fury when he was "strung out on coke, as big as a house" and contemplating suicide ahead of their rematch on Saturday.
WBC champion Wilder and Fury had to be separated following some pushing and shoving as they traded verbal punches ahead of a press conference on Wednesday.
The first fight between the heavyweight giants ended in a draw in December 2018, with Fury having revealed in the build-up to that bout that he was on the brink of ending his life two years earlier as he struggled with mental health issues.
Wilder claims former world champion Fury has a lot to thank him for as they prepare to do battle at the MGM Grand in Las Vegas this weekend.
"I brought you back, put food on your table," Wilder said.
"And I'm doing it for a second time. Don't you forget that.
"I found you when you were strung out on coke, as big as a house and contemplating killing yourself. I brought you to big-time boxing. I rehabilitated him back."
Fury had a sharp retort and vowed to end the American's career.
"He is spouting rubbish saying he gave me an opportunity," said the Brit.
"I gave him the biggest payday of his life, brought him to Las Vegas and this is how he thanks me. He has a lot of appreciation for someone who put millions in his account.
"I will put you into permanent retirement, don't you worry about that. This is a big act for him. He is nervous underneath, I can see his heart beating through his jumper, he is terrified and he is getting knocked out."