Pound-for-pound king Floyd Mayweather Jr has been stripped of the WBO welterweight belt after failing to pay a sanctioning fee.
The five-weight world champion secured the title by beating Manny Pacquiao on points in Las Vegas in May.
A $200,000 (£128,000) fee was required by July 3, but Mayweather, who recently claimed that he would relinquish the title, missed the deadline.
A statement on WBOBoxing.com read: "The WBO World Championship Committee is allowed no other alternative but to cease to recognise Mr Floyd Mayweather Jr as the WBO welterweight champion of the world and vacate his title."
The American WBA and WBC welterweight title holder has until July 20 to lodge an appeal.