Tyson Fury v Wladimir Klitschko II could take place in the United Arab Emirates, the champion's trainer Peter Fury has confirmed.
Fury (25-0-KO18) stunned world boxing in November when he seized the WBA Super, WBO and IBF belts from Klitschko (64-4-KO53) in Dusseldorf - and the Ukrainian subsequently activated a rematch clause.
Talks between the two camps over the terms of the second fight are ongoing, and the UAE are keen to stage a major boxing bout for the first time in the country's history.
Peter Fury told Sky Sports: "Everything is open at the moment but they are in the frame. We are dealing with it. We are looking at May, but it could be May 7, 14, 21 or 28. Nothing is fixed.
"There are many countries in the race at the moment and the UAE are in the running for sure. If the finances were all similar, of course we'd like to have it back here in England.
"All those tricks of the trade won't be an argument any more - the ring will be done properly, there'll be no dispute with the gloves and there'll be no more argument because everything will be correct."
There was controversy ahead of the first fight in Germany, as Team Klitschko made several attempts to take advantage of their fighter's status as defending champion on his adopted home turf.
There was a row over the use of the 39-year-old's choice of gloves, and just hours before the fight was due to start, a thick layer of foam was removed from under the ring canvas at Team Fury's request.
A further dispute arose when Klitschko wrapped his hands without a member of the opposing camp present but nothing could deter Fury, who won a unanimous verdict to end the champion's nine-and-a-half year reign.