NRL great Ian Roberts claims that he has irreversible brain damage due to repeated head injuries during his rugby league career.
The 52-year-old is among 25 former NRL players who last year took part in a study into concussions and the effects on the brain.
Roberts played 12 seasons in the NRL for the Rabbitohs, Sea Eagles and Cowboys along with higher honours in State of Origin and the Kangaroos. He revealed to the BBC that he was knocked unconscious at least 14 times during his career.
"I've had some complications with my mental health since retiring from rugby league," he told the BBC.
"My first major concussion was in my early teens, and when I turned professional I was knocked unconscious on 14 separate occasions."