Singer and songwriter Robin Gibb -- who with his brothers, Maurice and Barry, made up the Bee Gees -- is gravely ill in a London hospital, according to British media reports.
Although past reports have said he was battling liver cancer, Gibb has not acknowledged that publicly. Until recently Gibb, 62, seemed to be making what he called a "spectacular" recovery from surgery to remove a growth from his colon.
Then, late last month he was hospitalized for intestinal surgery.
According to the Sun newspaper, which cited a family friend Saturday, he now is in a coma.
PHOTOS: Robin Gibb
The newspaper and the Press Association news agency said family members including wife Dwina and brother Barry were at his bedside.
Maurice Gibb, Robin's fraternal twin, died at 53 of complications due to a twisted small intestine, which an autopsy determined was a congenital condition.
In August 2010, Robin Gibb had surgery for the same sort of blockage.
Gibb's publicist, Doug Wright, declined to comment, but Gibb's son has acknowledged that the 62-year-old musician is seriously ill in a hospital.
In a career that peaked with the disco music of 1977's "Saturday Night Fever," the Bee Gees have sold more than 120 million records. Closely associated with disco, the Bee Gees were also prime targets for the backlash against the genre.
But many argue that dismissing the group as less-than-worthy is a mistake. In 1997, the year the group was inducted into the Rock and Roll Hall of Fame, Times music critic Robert Hilburn wrote:
"Those views are shortsighted. Barry, Maurice and Robin Gibb injected an infectious dance floor pulse into their hits of the '70s, but the records had a style, individuality and grace that made them far superior to the standard disco fare of the period."
The group has had 15 top 10 records in the United States, including six consecutive No. 1 singles in the late '70s, and won six Grammy Awards.
Andy Gibb, the family's fourth brother and a solo artist, died of heart failure in 1988 at age 30 after years of struggling with cocaine addiction.