An all-British heavyweight showdown between Anthony Joshua and Tyson Fury in July or August is "dead in the water", according to Fury's promoter.
Joshua's promoter Eddie Hearn said on Thursday he was "100 percent confident" the fight would happen despite concerns over delays in finalising the super fight.
Saudi Arabia, where Joshua won a rematch against Andy Ruiz Jr in December 2019, has reportedly offered a huge sum to host the fight.
Bob Arum, though, believes it will not now be possible to complete negotiations in time and has called for the two boxers to arrange other fights.
"It will take months for the Saudis to do their due diligence on such a huge deal," Arum told the Telegraph.
"It is not just a site fee, there are ancillary demands from the Saudis stretching into the broadcast deals and other things. It could take months for it all to play out. It could even take until 2022 the way it looks right now.
"The fight in July or August is dead in the water as far as we are concerned. The two fighters need to go and have other fights this summer while the negotiations for that fight in the Middle East conclude.
"It is absurd what Hearn is saying that it is a done deal. If we had just done a site deal without all the other complications that have arisen, we would have a fight by now. Tyson Fury is fuming about it and is refusing to keep waiting."
The fight will be the richest in British boxing history, with the two men holding all four of the major world titles in the heavyweight division between them.