The man who played comedian, musician and North West showbiz legend Frank Sidebottom has died.
It is understood entertainer Chris Sievey collapsed at his home in Hale, Greater Manchester, in the early hours.
The 54-year-old was pronounced dead at Wythenshawe Hospital, a spokeswoman confirmed.
Known for his over-sized, papier-mache head, he found fame through a series of TV appearances in the 1980s and remained a popular cult comedy figure.
He had been recovering from treatment to a tumour on his chest, his agent Nigel Round said.
After having limited success with punk band The Freshies, Sievey created the role for which he will be best remembered.
Frank Sidebottom styled himself as an aspiring singer-songwriter from Timperley, south Manchester.
'One of a kind'
Often accompanied by his sidekick Little Frank - a glove puppet made in his own image - Frank became a regular face on TV in the 1980s and 1990s.
His TV fame peaked in the early 1990s with his own series Frank Sidebottom's Fantastic Shed Show.
David Behrens, who produced the series, said: "Chris was a genuinely funny and creative comic talent, and he had a huge and loyal base of fans.
"He had been ill recently but his death is terribly sudden and sad."
Mr Behrens added: "He came from a great comedy tradition in refusing to acknowledge his real identity when he was in character.
"As soon as the prop head went on, he'd answer to Frank, never Chris. A real one of a kind."
The comic creation's songwriting skills led to singles and EPs including Christmas Is Really Fantastic, and the Timperley EP.
Despite fading from TV in recent years, Frank continued to perform at gigs.
He appeared on stage only last week, his agent said.
Mr Round said the comedian downplayed the cancer he had been fighting in recent months.
"He always said it was no problem, he was going through treatment but it was being sorted out."
Mr Round added: "He was just a nice bloke. He was quite a private person. He never spoke about Chris Sievey, it was all about the character."
He said Sievey was planning to come out from under the papier-mache mask in the coming years.
"Everyone kept it really quiet. We were probably only 12 months from him uncovering himself," Mr Round said.