The Senegalese striker has told West Ham he wants to quit on a free transfer but his demands are apparently putting off Everton, Newcastle and Sunderland.
Ba has several agents working on his deal and the figures put to potential takers have come as a shock and delayed any move.
Ba believes he has a release clause in his contract and has formally written to West Ham to tell them he wants to leave and become a free agent.
But the Londoners think they still have a claim on him and now the dispute is in the hands of lawyers who are studying the fine print of his deal, signed when he joined from German side Hoffenheim in the last transfer window.
West Ham want him to stay at Upton Park and think they can demand a fee if they cannot talk him into that.
Any significant fee for Ba’s services would effectively put Everton out of the running for his signature.