Robin Gibb is in coma at a hospital in London, according to a report from British tabloid The Sun.
The family of the singer is at his bedside amid fears he has only days to live, according to the report.
"Our prayers are with Robin. He has kept so positive and always believed he could beat this," a family friend told British tabloid The Sun.
The former singer of the Bee Gee's recently made a recovery from cancer but is fighting pneumonia.
The Bee Gees was formed in 1958 and earned great success for many decades. Among their greatest hits are "Massachusetts," "Stayin Alive" and "I've Gotta Get A Message To You."
Most recently, Gibbs premiered his first classical work "The Titanic Requiem," which is being released to mark the 100th Anniversary of the sinking of the Titanic.