London (CNN) He was "the kindest, most generous soul and a brilliant artist," Elton John wrote on Instagram in one of the many tributes to pop star George Michael, who died at 53 on Christmas Day. The singer is believed to have died from heart failure, his manager Michael Lippman said, according to the UK-based Press Association. Michael's death, which is being treated as "unexpected but not suspicious" by police, was also confirmed by the singer's family. "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," his family said in a statement.Wham! star George Michael is dead at the age of 53Singer died at his home in England, family confirms
"From the enormous success he achieved with pop duo _.