Former world heavyweight champion Tyson Fury says he will not reapply for a licence to fight from the British Boxing Board of Control.
The 29-year-old had his licence revoked in October 2016 after allegations of doping emerged in June.
Fury, who hinted at a comeback in March, tweeted: “After thinking long and hard about my return, I will not be applying for a BBBofC boxing license.”
“After the way they have handled stuff, no thanks.”
His decision not to seek a new licence casts Fury’s future as a boxer into doubt again, although he has previously appeared to end his career via social media.
In October 2016 he tweeted: “I’m the greatest, and I’m also retired” before performing a u-turn three hours later.
But he has not fought since November 2015, when he shocked Wladimir Klitschko in Dusseldorf to claim the IBF, WBO and WBA world titles.
Fury pulled out of one rematch scheduled for July 2016 with an ankle injury, before withdrawing from a second that was slated for the following September by saying he was “medically unfit”.
The British Boxing Board of Control has previously said it will not reinstate Fury’s licence to fight until a UK Anti-Doping hearing into a positive test he returned in February 2015 has taken place.
The testing authority said in September it is attempting to resolve Fury’s case “as quickly as possible” after being criticised by the Manchester fighter for taking too long to conclude its investigation.
Fury admitted in a 2016 interview with Rolling Stone magazine that he was taking cocaine and struggling with mental health problems.
During his absence from the ring he has been stripped of the three belts he won by outpointing Klitschko in one of the great boxing upsets of all time.