Frank Warren has said that he does not understand why James DeGale wants to leave his stable.
The European super-middleweight champion decided to part company with Warren last month, saying it was "time to move on".
However, Warren has told the Olympic gold medallist that he must go through the British Boxing Board of Control if he wants to split from his banner.
"I haven't been in contact with James since December, that's the last time we spoke," Warren told The Sun. "It's very disappointing but he obviously feels he has a gripe and he's entitled to feel that way.
"I don't believe I've done anything untoward to him. He's European champion and I work very hard on his behalf. James has done well financially and he's in a good position as far as boxing is concerned right now. But if he feels he has a problem then the correct process is to go through the BBBofC.
"To be quite honest, I'm not sure what it is myself. The board have asked him to spell out what it is."
DeGale won the European super-middleweight strap after beating Piotr Wilczewski at the Echo Arena in October.