Tyson Fury has given up his WBO and WBA heavyweight titles to concentrate on his "medical treatment and recovery".
The boxer said he was handing back his belts with immediate effect before he could be stripped of the titles following his admission that he had taken cocaine as he battled depression.
The 28-year-old has cancelled two planned rematches against Ukrainian former champion Wladimir Klitschko.
Fury said in a statement: I feel that it is only fair and right and for the good of boxing to keep the titles active and allow the other contenders to fight for the vacant belts that I proudly won and held as the undefeated heavyweight champion of the world when I defeated the long-standing champion Wladimir Klitschko.
I won the titles in the ring and I believe that they should be lost in the ring, but I’m unable to defend at this time.
Mick Hennessy, Fury’s promoter, said the decision was heartbreaking.
Peter Fury, Tyson’s uncle and trainer, said: Tyson will be back stronger from this and I will make sure, no matter what we have to deal with, Tyson not only comes back but will reclaim what’s rightfully his.
I’m very proud of my nephew’s achievements.
Fury had withdrawn from a rematch with Klitschko later this month because of mental health issues.
The outspoken boxer admitted in an interview with Rolling Stone magazine that he was suffering from depression and taking cocaine.
The British Boxing Board of Control met on Wednesday to discuss whether to remove Fury’s boxing licence following the admission of drug taking. They had been due to release their decision on Thursday.
(c) Sky News 2016: Tyson Fury gives up world titles to concentrate on recovery