Promoter Frank Warren says Tyson Fury's heavyweight fight with Oleksandr Usyk is off - and he "does not think" it will happen in the near future.
Talks over a bout at Wembley Stadium on 29 April have broken down, despite a late bid to salvage the situation.
Usyk had agreed a 70/30 purse split in Fury's favour with terms for a rematch the only outstanding issue.
But Warren said the fight is now a "dead duck" and suggested Usyk had looked "for a way to get out".
"They said the fight must take place before 29 April and if it goes later they want different splits," Warren said.
"The reason they did that was they didn't think Tyson would be ready for the 29th and suddenly Tyson was ready for it.
"He has been in training camp for two and a half weeks, got trainers in from America and they looked for a way to get out."
Fury currently holds the WBC heavyweight belt while Ukraine's Usyk, who beat Britain's Anthony Joshua for a second time last year, has the others in the division.
Warren said Fury had agreed to the principle of a rematch but terms around the deal, and whether it would again be for all of the belts, had not been finalised.
He said Usyk's camp have also been "turned" by potential earnings by fighting in Saudi Arabia later this year by which time Usyk would have to fight other mandatory challengers.
"There is an established rota of who Usyk has to defend against," Warren said.
"That's why after the 29th it goes away."
Both parties have until 1 April to agree a deal after the WBA said it would wait until that date before ordering Usyk to fight mandatory challenger Daniel Dubois.
A breakthrough in talks, followed by another obstacle
When Fury, 34, beat Derek Chisora in December to retain his WBC title, he said agreeing a deal with Usyk and his team for an undisputed fight would be easy - but that has not proven to be the case.
After months of back and forth, Fury publicly declared 12 days ago he would not accept anything less than a 70/30 purse split in his favour.
Usyk surprised everyone by accepting that offer, despite holding three of the four world titles, and subsequently informed governing body the WBA that terms had been reached.
However, Fury then said he would not sign any deal that included a rematch clause - leading to a conference call on Sunday morning between all parties.
Warren said "six or seven" outstanding issues were ironed out and he had managed to convince Fury to accept a rematch. The WBC champion agreed and the call ended with Team Fury optimistically preparing an official statement to announce the fight.
Warren teased on Twitter on Sunday that news was imminent, but the two sides again clashed over the proposed terms of a rematch.
According to Warren, Fury was against an immediate rematch in part as he did not want to be tied into two fights against Usyk as he was with Deontay Wilder, which meant he could not fight British rival Anthony Joshua.
The purse splits for a proposed rematch appear, however, to be the key unresolved issue to unlocking Fury v Usyk.
'Why are we even talking about rematches?'
Usyk, the WBA (Super), IBF, WBO and Ring magazine champion, would like a proposed rematch to happen in November or December, but there are fears among Team Fury that the four belts would have fractured by then.
WBC president Mauricio Sulaiman contacted the Fury camp on Wednesday to say the governing body could not guarantee its support for an immediate rematch.
Usyk, 36, wants a rematch clause like the one Joshua activated when they fought in 2021. The Briton was given the chance to immediately regain the titles and Usyk would want the same opportunity if he was beaten by Fury.
But if the Ukrainian overcame Fury in their first fight, he would also expect an improved purse split in a rematch.
There has not been an undisputed heavyweight champion since 1999 when Lennox Lewis beat Evander Holyfield - and never been one in the four-belt era.