Ricky Hatton could be forced to give up his IBF light welterweight title if he takes on Mexico's Jose Luis Castillo in his next fight.
Hatton had to battle hard to get past Juan Urango
The Briton regained the belt with a tough points win over Colombia's Juan Urango in Las Vegas earlier this month.
The IBF says he must next fight the winner of Sunday's contest between Naoufel Ben Rabah and Lovemore N'dou.
"If Hatton says he will fight Castillo next, I will have to vacate the title," said IBF president Marian Muhammad.
Hatton has reportedly been given until Friday by the IBF to make a decision on his next fight.
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If Hatton decides to go ahead with the Castillo fight in the summer, next Sunday's bout in Sydney between Ben Rabah and N'dou could then become a world title fight.
"When Juan Urango fought Hatton, it was on an exemption because the mandatory was already due," Muhammad told the SecondsOut website.
"You can't get two exemptions to further delay a mandatory.
At this stage in Ricky's career the names are bigger than the titles
Hatton's promoter Dennis Hobson
"My thought is that Hatton has only had the title for nine days, he should be given the opportunity to make up his mind what he wants to do.
"He won the title in the ring fair and square. What I didn't want to do is be unfair to Naoufel Ben Rabah and Lovemore N'dou."
Dennis Hobson, Hatton's promoter, said: "We have got the Castillo fight on the table but there is also the option for Ricky of coming back to Manchester to fight Ben Rabah or N'Dou, then taking on Castillo after that.
"It all comes down to whether Ricky wants to hold onto his title but the IBF
have got to give him time to make his mind up."
However neither Hatton's camp or American television network HBO are likely to be too bothered at the prospect of giving away the belt again.
"At this stage in Ricky's career the names are bigger than the titles and I know HBO are totally unconcerned about whether a title is on the line in his fight with Castillo or not.
"When you are making your way up the titles mean more but, at this stage, although we maintain a good relationship with the IBF, the titles can
become more of a hindrance than anything else."