Wladimir Klitschko has announced he is planning to take world heavyweight champion Tyson Fury to court over their proposed rematch.
Klitschko and Fury were scheduled to meet in Manchester on July 9, but the fight was postponed until October 29 after the Briton suffered an ankle injury.
It subsequently emerged that Fury had also been serving a provisional suspension after being charged with having a banned substance in his system. That ban has since been lifted pending a hearing in November.
Klitschko lost to Fury in Dusseldorf in November last year and talks over their second bout appear to have broken down after Klitschko posted an update on social media.
"Dear fans. I just want to keep you updated on the status quo of my rematch against Fury," Klitschko said in a video.
"Unfortunately, Team Fury is trying to change the terms of an already-signed contract multiple times. To protect my own rights and eventually see the rematch, I'm forced to go to court."
Fury, who is yet to respond, said earlier in the week that he plans to fight IBF champion Anthony Joshua and WBC title holder Deontay Wilder after facing Klitschko.