David Haye has split from his trainer Shane McGuigan, the 36-year-old fighter has announced on his official Facebook page.
Haye is currently recovering from an Achilles tendon injury suffered in his bout against Tony Bellew in March.
"Shane and I have come to the mutual decision that when I am ready to go back into full training, we will no longer be working together as boxer and coach," wrote Haye.
"We remain good friends and will always metaphorically be in each other's corner but both parties agreed moving forward we weren't right for each other.
"I remain deeply indebted to Shane for playing a pivotal role in my comeback to date. I will forever be grateful for his hard work and tutelage. I would not be in the position I am today without this."
McGuigan responded on Twitter: "Myself & @mrdavidhaye have mutually decided to part ways. I wish him all the success in his future endeavours. We remain good friends."
Haye won the WBA heavyweight title against Nikolai Valuev in 2009 and defended it twice before losing to Wladimir Klitschko, after which he retired two days shy of his 31st birthday.
He returned once to fight Dereck Chisora in 2012, winning by fifth-round stoppage, and again in 2015 for three fights to date, culminating in the 11th-round loss to Bellew.
Regarding his injury, Haye wrote: "I'm pleased to confirm rehabilitation is going well and I will make a complete recovery.
"Whilst I am not quite in a position to be announcing my next opponent, my passion for the sport remains unwavered and desire to regain my heavyweight title is stronger than ever."