Paul Cattermole, who rose to fame as part of the London pop group S Club 7, has died aged 46.
The group shared a statement on Twitter as the news broke of his passing, saying he will be "deeply missed" by them all.
It read: "We are truly devastated by the passing of our brother Paul. There are no words to describe the deep sadness and loss we all feel.
"We were so lucky to have had him in our lives and are thankful for the amazing memories we have."
His passing comes just weeks after the group announced it was reuniting for a major tour.