Culture Club have cancelled their forthcoming US and UK tour because singer Boy George has developed a throat condition and may need surgery.
The reunited 1980s pop idols were due to embark on their first tour for 12 years on Saturday in California.
But Boy George has found a polyp on his throat, which may need to be removed.
The star said: "I want to be able to perform to the best of my ability and the specialist has told me that right now that will be impossible."
The singer said he was "devastated", adding: "I will focus on getting better and see all my fans soon."
The group were due to play 10 shows in the US before beginning an 11-date UK arena tour in Glasgow on 1 December.
A statement said: "The throat specialist has ordered George to not sing as it may necessitate an operation."
The band said: "We are hoping we can reschedule the concerts for next year, and hopefully George's problem will be resolved."
This was to have been the first tour featuring Boy George, bassist Mikey Craig, guitarist and keyboardist Roy Hay and drummer Jon Moss since 2002.
They have already recorded a new album, Tribes, which is due to be released early next year.
A polyp is a fluid-filled collection that forms when a vocal cord is not rested enough. Singers including Bjork, Adele and Keith Urban have had them removed in recent years.
