His manager, Michael Lippman, said he had died of heart failure.Police say they were treating the death as unexplained but there were no suspicious circumstances.
In a statement, the star's publicist said: "It is with great sadness that we can confirm our beloved son, brother and friend George passed away peacefully at home over the Christmas period.
"The family would ask that their privacy be respected at this difficult and emotional time. There will be no further comment at this stage."
In 2011, Michael postponed a series of concerts after being taken to hospital for treatment for pneumonia.
After treatment in a Vienna hospital, he made a tearful appearance outside his London home and said it had been "touch and go" whether he lived.
Doctors were said to have performed a tracheotomy to keep his airways open and he was unconscious for some of his spell in hospital.
