FORMER US professional boxer Rubin 'Hurricane' Carter, who spent 19 years in prison for murder and then was released after it was determined he did not get a fair trial, has died at the age of 76.

Carter, considered a folk hero by many and immortalised in film and song, had been battling prostate cancer for nearly three years, his friend and caretaker John Artis said.

He died at home in Toronto, where he had been living since he was released from prison in 1985.

"Those who are wrongfully incarcerated lost a champion," Mr Artis said. "He dedicated his life to helping the people that need the same kind of assistance that we needed, who have been wrongfully convicted and incarcerated."

Once a middleweight boxer who earned a world title fight in 1964, Carter is more well known for the turn his life took after he was arrested for a triple homicide in 1966.

That arrest, his imprisonment, and the ultimately successful battle to free him are immortalized in the 1975 Bob Dylan song 'Hurricane' and the 1999 film of the same name, which starred Denzel Washington as Carter.

Born in 1937 in Clifton, New Jersey, Carter ran into trouble with the law as a teenager, serving custodial sentences for assault and robbery, and spending two years in the army.

In his 1974 autobiography titled "The Sixteenth Round", Carter wrote of his younger years: "The kindest thing I have to say about my childhood is that I survived it."

In 1961, he channelled his energies into boxing, turning pro and earning a 1964 title match against world champion Joey Giardello, which Carter lost in a unanimous decision.