Bee Gees singer Robin Gibb has died following a lengthy battle with cancer and intestinal surgery, his family said on Sunday.
Gibb, 62, was battling colon and liver cancer and was recently hospitalised with pneumonia.
In a statement, Gibb's family said they were announcing his death with "great sadness".
Gibb had surgery on his bowel 18 months ago for an unrelated condition, but a tumour was discovered and he was diagnosed with cancer of the colon and, subsequently, of the liver.
On Robin Gibb's Facebook page, a status update on Sunday read, "Our sweet hero has gone to heaven to sing with the angels."
The statement said: "The family of Robin Gibb, of the Bee Gees, announce with great sadness that Robin passed away today following his long battle with cancer and intestinal surgery. The family have asked that their privacy is respected at this very difficult time."
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Gibb's son, Robin-John, 29, had been due to premiere a collaborative classical work, The Titanic Requiem, with his father in April, but the event went ahead without Gibb due to his poor health.
The Bee Gees' song catalogue, which includes Massachusetts, I've Gotta Get A Message To You, Lonely Days, How Can You Mend A Broken Heart, How Deep Is Your Love and Stayin' Alive, led to their induction into both the Rock and Roll Hall of Fame and the Songwriters Hall of Fame.
Gibb's twin brother Maurice died of a heart attack in 2003 following intestinal surgery.
Gibb's younger brother Andy, who was not part of the Bee Gees but a successful singer in his own right, died in 1988 from heart failure at 30.
A statement from Sony Music on Twitter said: "Rest in peace, Robin Gibb. Thanks for the music."
Radio disc jockey Mike Read, who was a family friend of Gibb, said the singer had an "incredible voice".
"Robin had the voice, the pathos, and he was a great writer," he added in remarks to BBC Radio 5 Live.
"In his head he could come up with some great melodies. I was delighted to work with him. He had a gift for melody and a gift for lyrics and left a phenomenal legacy, a phenomenal catalogue."
Referring to the Bee Gees, the former BBC Radio One DJ said: "They had every accolade under the sun. They were able to write great commercial songs that touched people over a very long period of time. They had every award, every gold disc, every platinum disc, the Grammys the lot and had been doing it so long but were still so good at it."
Broadcaster Paul Gambaccini said Gibb was "talented beyond even his own understanding".
He said: "Everyone should be aware that the Bee Gees are second only to Lennon and McCartney as the most successful songwriting unit in British popular music.
"Their accomplishments have been monumental. Not only have they written their own number one hits, but they wrote huge hit records for Barbra Streisand, Diana Ross, Dionne Warwick, Celine Dion, Destiny's Child, Dolly Parton and Kenny Rogers, the list goes on and on.
"What must also be said is Robin had one of the best white soul voices ever. He was singing lead on his first number one when he was 17, that was Massachusetts."