Tyson Fury has claimed that Deontay Wilder has asked for a $20m fee to step aside to allow him to fight Anthony Joshua.
A court of arbitration ruled this week that Fury must fight Wilder again by September 15 which would scupper plans for an undisputed title fight against Joshua on August 14.
"What a joke the Bronze Bomber has become," Fury posted on social media on Tuesday night.
"Asked for $20m to move over, joker.
"Looks like I have to [fight him] again."
However, Wilder's new trainer Malik Scott insisted they want to fight Fury and won't accept a pay-off: "No. Wilder declined and had no interest in step aside money. You are dealing with a whole different type [of mentality] over here. He wants the blood not the step aside money.
"'Retribution is upon us'."
Fury called Wilder a "reptile" and added: "This is how I'm feeling right now. I'm on the inside fighting, smashing stuff up, and my next opponent is getting smashed to bits!"
Isaac Lowe, Fury's training partner, said: "Whoever is next for this man it's not going to go past six rounds. The Gypsy King is the man and is ready to fight."
Fury has since posted a picture mocking the reasons that Wilder gave for losing the WBC belt when they fought for a second time.
"No excuses… but," Fury's tease began.
"Costume was too heavy, Fury's gloves were loaded, I had weak legs, my water was spiked, Fury's gloves had no padding, had bicep surgery, disloyal trainer, complications in camp, I broke my arm, fight stopped too early, Andre Dirrell's fault."
Fury dismantled the previously-unbeaten Wilder in February 2020.
Wilder has since parted ways with his trainers and is working alongside his former opponent Malik Scott.
Will Joshua now fight Usyk?
WBO president Paco Valcarcel said on Tuesday night: "I hope boxing fans will enjoy Joshua vs Usyk in the near future."
Usyk was named as Joshua's "Plan B" option by promoter Eddie Hearn.
The undefeated Ukrainian is a former undisputed cruiserweight champion and is now the WBO mandatory challenger to the belt held by Joshua.
"There is no other reasonable excuse for AJ now," Usyk's promoter Alexander Krassyuk told Sky Sports.
"If he is not avoiding Usyk, it is high time to face the mandatory!
"Two London Olympic champions to face each other, nine years later. What a story.
"We are now in the position to make the fight happen as soon as possible."
Can Joshua vs Fury still happen?
Hearn said: "I hope. But am I hopeful? I don't know.
"We were told the arbitration wouldn't be a problem but obviously it is a problem.
"We have to think on our feet. We have to act accordingly. We still hope the fight can go ahead but it's out of our hands.
"The positivity from Team Fury was great for everybody. They had started training camps.
"[Joshua told me]: 'Take care of it, let me know, I'll be in the gym'.
"We know what we want - to win the undisputed championship and to fight Fury. But if his hands are tied we have to look elsewhere."