Former world heavyweight champion Joe Frazier has died aged 67.
It emerged over the weekend that Frazier was fighting liver cancer and he was reported to be in hospice care.
And a family statement reported by Philadelphia's WPVI-TV read: "We, the family of the 1964 Olympic boxing heavyweight gold-medallist, former heavyweight boxing champion and International Boxing Hall of Fame member Smokin' Joe Frazier, regret to inform you of his passing.
"He transitioned from this life as ‘One of God's Men,’ on the eve of 7 November, 2011 at his home in Philadelphia, Pennsylvania. We thank you for your prayers for our father and vast outpouring of love and support.
"Respectfully, we request time to grieve privately as a family. Our father's home going celebration will be announced as soon as possible. Thank you for your understanding."
Frazier won Olympic gold in 1964 after going to the Games as a replacement for the injured Buster Mathis, who had beaten him in the trials.
He won the professional heavyweight title in 1970 by stopping Jimmy Ellis in the fifth round at Madison Square Garden and defended it successfully four times before losing it to George Foreman in 1973.
Frazier is best remembered for his three bouts with Muhammad Ali, the first of which saw him unify the world title when he inflicted Ali's first professional defeat in the so-called 'Fight of the Century' in 1971.
But in two further fights, including the epic 'Thrilla in Manila' in 1975, it was Ali who was victorious.
Ali, 69, said: "The world has lost a great champion. I will always remember Joe with respect and admiration. My sympathy goes out to his family and loved ones."
Boxing stars of a more recent era took to Twitter to share their thoughts, with Floyd Mayweather writing: "RIP Smokin Joe. My thoughts and prayers go out to to the Frazier family. We lost an all time great tonight."
The fighter known as 'Money' continued: "My Condolences go out to the family of the late great Joe Frazier. #TheMoneyTeam will pay for his Funeral services."
Oscar De La Hoya wrote simply: "I will miss you my friend. R.I.P. Joe frazier."
Frazier retired in 1976 after losing a rematch against Foreman, and aborted an attempted comeback five years later after a draw with the unheralded Jumbo Cummings.