Amir Khan demanded an 80-20 purse split in his favour to fight IBF welterweight champion and domestic rival Kell Brook, says Brook's promoter Eddie Hearn.
Khan, a former light-welterweight world champion, had taken to Twitter to accuse Brook of ducking him.
Khan added that Brook's demand of a 50-50 split was unacceptable.
Hearn said Brook would be happy to take the thin end of a 60-40 split and that he would continue to negotiate with Khan's team on that basis.
Hearn added that Khan's team had demanded more than £7m to fight Brook, which would have left Brook with £2.5m at most.
Hearn later told Sky Sports News: "He [Khan] is trying to price himself out of the fight because he doesn't want it.
"It's been very positive for the last few weeks and when there is dialogue it's always good. But I was left gobsmacked by their demands.
"I appreciate Khan is probably a bigger name than Kell Brook but Kell Brook is world champion and he needs some kind of parity. More importantly, he needs some respect."
Brook also weighed in to the row tweeting: "There you have it Amir Khan, put up or shut up. No more talk, June 4 Wembley stadium for the world title. I will destroy you."
Khan had hoped to fight Manny Pacquiao this year, but when Pacquiao decided to take a deciding match against Timothy Bradley instead it looked like a fight against Brook was a near certainty.
However, Khan's latest Twitter outburst - in which he mocked Brook for fighting "bums" and ducking the best in the welterweight division - would suggest that is not the case.
Bolton's Khan, who had also hoped to fight Floyd Mayweather last year before the American legend's retirement, says he would like a rematch with Danny Garcia next.
The unbeaten Garcia, who knocked Khan out in 2012, faces fellow American Robert Guerrero in Los Angeles on Saturday.
Khan, 29, has not fought since outpointing Chris Algieri in New York last May and has not held any world titles since losing to Lamont Peterson in 2011.
Sheffield's Brook, also 29, has also not fought since last May, when he stopped fellow Briton Frankie Gavin. Brook faces a mandatory defence against unheralded Canadian Kevin Bizier in March.
Meanwhile, Khan says Pacquiao's suggestion a fight between the two men was nixed by Khan's team "are wholly inaccurate and false".
"An initial meeting took place last September between [Pacquiao's promoter] Bob Arum and my uncle and lawyer in London," said Khan.
"My team was told by Bob Arum that it was a choice between either [WBO light-welterweight champion] Terence Crawford or myself.
"[Pacquiao's] team knew a fight between us would be a very dangerous one for him and best avoided. A fight with Bradley - who Pacquiao in most opinions has beaten twice - is a much easier option."