DIGEST: Robin Gibb, A Life In Pictures
Bee Gees pop legend Robin Gibb was in a coma last night, amid fears he has only days to live.
The 62-year-old's family are understood to be at his bedside, The Sun reports.
A friend said: "Our prayers are with Robin. He has kept so positive and always believed he could beat this.
"If there is anyone you would put money on pulling through such a dire situation, it would be Robin because he is a fighter. But this is a battle he will struggle to win."
Gibb has been battling colon and liver cancer and was recently hospitalised with pneumonia.
Scroll down for a gallery of images of Gibb and the Bee Gees
He was forced to pull out of a performance at the Royal Philharmonic's premiere performance of The Titanic Requiem in London on April 10, because he was so ill.
An spokesperson for the star said: "On Sunday 25 March, Robin Gibb underwent further intestinal surgery.
"He is currently recovering in hospital and therefore, for the time being, all existing commitments prior to The Titanic Requiem concert, have had to be cancelled."
His son Robin-John, who co-wrote the symphonic piece, told the audience that his father was still recovering in a clinic.
Before the performance, he said: "He sends all his love. We are all praying for him and hoping he has a speedy recovery."
Last month the star told The Mirror he felt "fantastic".
"'I am beating cancer and can't wait to carry on with my work," he said.
The Bee Gees (L-R) Barry, Maurice, Robin Gibb at Heathrow Airport, London, before leaving for a 3 month World Tour. 1974
The Bee Gees, (l to r) Robin, Barry and Maurice Gibb, accept the Brit Award for Outstanding Contribution in 1997
The Gibb brothers: Barry (centre) and twins Maurice (left) and Robin (right)
Bee Gees Singer Robin Gibb reads to his son Spencer, circa 1974
Bee Gees Singer Robin Gibb with his wife Molly Hullis (r) and two children Spencer and Melissa in his home, circa 1974
The Bee Gees, back row, left to right: Barry Gibb, Robin Gibb, and Vince Melouney. Front, left to right: Dennis Bryon and Maurice Gibb. 1967
Robin Gibb, founding member of the Bee Gees, unveils a plaque honouring the work of the Bee Gees at 67 Brook Street, central London. 2008
Robin Gibb performs at the BBC Electric Proms 2008 - Saturday Night Fever at the Roundhouse, Chalk Farm, London.
Official ambassador Robin Gibb CBE (centre) with his wife Dwina and son arriving for The Sunseeker International Charitable Trust Ball - in aid of The Outward Bound Trust - at Battersea Evolution in south London. 2009
Robin Gibb and his wife Dwina at No.11 Downing Street in London for the Diana Awards.
Members of the Bee Gees pose with Barry Manilow, far right, at the American Music Awards in Los Angeles, Ca., Friday, Jan. 13, 1979. The brothers Gibb, from left, Barry, Maurice, and Robin, won awards for favorite popular group and favorite soul album
The Bee Gees, from left, Robin, Barry and Maurice Gibb, attend a party in 1978
Andy Gibb eats a cherry from his birthday cake at a party given by his family in his home in Miami Beach, Fla., Monday night, March 6, 1979. Andy's brothers, the Bee Gees, from left are, Robin, Barry and Maurice. (AP Photo)
British singer Robin Gibb arrives for the 46th Goldene Kamera (Golden Camera) media award gala in Berlin, Germany, Saturday, Feb. 5, 2011