Kiwi UFC heavyweight star Mark Hunt is beginning to suffer symptoms of brain damage.
Writing for Australian website Player's Voice, Hunt, 43, revealed that he is starting to experience loss of memory, as well as stuttering and slurring his words as a result of his 16-year combat sports career, which has seen him involved in K-1 kickboxing and the PRIDE Fighting Championships in addition to UFC.
"Sometimes I don't sleep well. You can hear me starting to stutter and slur my words," he said.
"My memory is not that good anymore. I'll forget something I did yesterday but I can remember the s*** I did years and years ago.
"That's just the price I've paid - the price of being a fighter. But I've fought a lot of drug cheats and copped a lot of punishment from guys who were cheating and that's not right."
Hunt has been a strong advocate against the use of performance-enhancing drugs throughout his mixed martial arts career, notably filing a lawsuit against former UFC fighter Brock Lesnar following his defeat to the American wrestler last year.
"If you take away all my fights against juicers, it would probably be half of my fight record gone," said the 'Super Samoan', who currently has a 13-11-1 record in MMA.
"I used to be a little bit naive. I didn't realise this until after the Brock Lesnar fight. I would sign fight contracts on the presumption that my opponent was clean. When they break that contract and cheat, it's like trying to fight a shark in the ocean.
"Doping has been a part of the sport for a long time because there is a lot of money at the top."
Hunt, who has three fights remaining on his UFC contract, is set to next step in the octagon in November when he takes on Polish fighter Marcin Tybura in Sydney.