US former boxer Rubin "Hurricane" Carter, whose wrongful conviction for murder caused an international outcry, has died at the age of 76.

He died on Sunday at his home in Toronto, Canada, his friend and former co-defendant John Artis, confirmed.

Carter spent 19 years in prison for three murders in New Jersey in 1966.

The alleged racial motivations behind the incarceration became well-known in Bob Dylan's song Hurricane, several books and a film.

Artis said Carter had died in his sleep, following a battle with prostate cancer, AP news agency reported.

Carter was charged with three murders in New Jersey in 1966. He was retried and convicted again in 1976, before eventually being freed for good in 1985.

A high-profile campaign involving supporters including Bob Dylan and Muhammad Ali had advocated for him to be freed.

The judge who ordered his release in 1985 said Carter's convictions had been "predicated on an appeal to racism rather than reason, and concealment rather than disclosure".