Promoter Eddie Hearn has said that the demands made by both Chris Eubank Jr and Chris Eubank Sr made it "impossible" to push through a deal to face Gennady Golovkin.
After lengthy negotiations, Golovkin and Eubank Jr had been expected to meet in London in September but on Friday night, Hearn caused a huge surprise by announcing that IBF welterweight champion Kell Brook would step up two weight divisions to meet the best pound-for-pound fighter in the world.
Speculation soon intensified as to why Eubank Jr had not signed to take the fight, but Hearn has suggested that the Eubanks had missed a deadline to accept his conditions for the bout.
Hearn told Sky Sports News: "I worked for three weeks on that fight, negotiating with Chris Eubank Sr. It felt like three years.
"We got into a position where everybody was ready to sign. [Eubank Jr] was offered the same pay-per-view deal as Anthony Joshua, Carl Froch and the one that Kell Brook accepted.
"Unfortunately [the Eubanks] made the deal impossible. The things they wanted were just a complete no-go. They were given a deadline and they chose not to take the fight."
In an interview with iFL TV, Hearn said that the Eubanks wanted "full operational control" of the pay-per-view event at the O2 Arena.