Carl Froch's promoter has objected to the appointment of Jack Reiss as referee for the George Groves rematch and officials must find a replacement.
Groves called for a foreign referee to oversee the second fight, live on Sky Sports Box Office, after Englishman Howard Foster controversially signalled a stoppage win for Froch in their first meeting in November.
Reiss, a highly experienced American, was originally chosen as the man in the middle for their Wembley clash on May 31st.
But Froch's promoter Eddie Hearn raised concerns about the Californian after he took charge of Bermane Stiverne's WBC heavyweight title win over Chris Arreola last weekend.
"The officials have yet to be finalized," said Hearn.
"The initial list was sent out but was objected by both parties; one on the referee and the other on one of the judges.
"We now have to wait to see who the IBF bring forward."
A list of alternative officials will be submitted to the British Board of Boxing Control for their approval before another referee is selected.
Lindsey Tucker, IBF Championships Chairman, told Sky Sports: "Well we initially wanted Jack Reiss, but we've got an objection, so we've had to change.
"We naturally feel that Reiss is qualified to do the fight, but a big fight like this, if somebody objects we kind of take it seriously, even though we don't agree with this, we kind of take it seriously.
"We don't want anybody to come back later and say well if you had changed... so we're thinking about switching.
"The next step now is to send a couple of names to the British Board to see if they will agree with any of them and then we'll go from there.
"I would think we'll probably know by Friday."
Watch Froch-Groves II on Sky Sports Box Office on May 31
Tags: Carl Froch , George Groves , Eddie Hearn , Froch-Groves , Froch vs. Groves