Bay City Rollers guitarist Alan Longmuir has died at the age of 70.
Mr Longmuir had recently returned to Edinburgh for treatment after reportedly falling ill while on holiday.
His death was confirmed by journalist Liam Rudden, writer of the Bay City Rollers musical I Ran With the Gang.
He tweeted a statement from Mr Longmuir's family which said: "We are devastated to share the news that Alan has passed away peacefully surrounded by family.
"He was an extraordinary man with an extraordinary heart.
"He brought so much love and kindness to everyone he met, and he leaves a huge hole in our family.
"He would humbly say he was 'just a plumber from Edinburgh who got lucky'. However, we are the lucky ones; the ones that were lucky enough to have Alan as part of our lives.
"We'd like to thank everyone for the love and support that they have provided so far."
Mr Rudden added: "Devastated by the news my friend @alanlongmuirbcr has left us.
"He was one of the most gentle, generous & kind-hearted people I've ever known & touched the lives of all he met with a smile that made them feel special."
Formed at the end of the 1960s, the Bay City Rollers enjoyed huge success at home and abroad with their distinctive tartan outfits and upbeat pop tunes like Bye Bye Baby and Shang-a-Lang.
They had a massive teen following and sold more than 100 million records.
Longmuir joined band members Les McKeown and Stuart Wood for a Bay City Rollers union in 2015 with gigs quickly selling out.
The original line-up also included Eric Faulkner and Longmuir's younger brother Derek.
The band rose to fame producing numerous top 10 hits, sell-out tours and their own TV show before splitting in 1978.
Frontman McKeown tweeted a picture of Mr Longmuir in his youth with a caption reading: "RIP Alan Longmuir... the original Bay City Roller."