Veteran stage and screen actor John Woodvine is in a stable condition in hospital after collapsing while performing in a musical.
During his long career Woodvine, 82, has performed alongside Sir Ian McKellen and Dame Judi Dench as Banquo in Macbeth, and is well known for his role as Detective Inspector Witty in the 1960s TV police drama Z Cars.
More recently he played Frank Gallagher's father Neville in the Channel 4 comedy drama Shameless, and his film credits include An American Werewolf In London.
But during his latest performance as the Star Keeper in the musical Carousel, Durham-born Woodvine collapsed in the wings at the Grand Theatre in Leeds.
The actor, who had a long career with the Royal Shakespeare Company, is in a stable condition in hospital, according to show producers Opera North.
John Wilford, 71, was among the audience and told how they were informed the show would not go on after Woodvine was taken ill.
The retired journalist from Leeds said: "Suddenly the action on stage appeared to slow down and stumble. Then suddenly the safety curtain came down. A man reached into the orchestra pit and told the conductor to stop playing. He jumped on stage and said: 'Is there a doctor in the house?'
"There was a surprised silence. When we were told the show was stopped, the audience took a moment to digest it and then stood up and applauded."
A member of staff said Woodvine collapsed about ten minutes after his first entrance, soon after the performance of the classic show tune "You'll Never Walk Alone".
Woodvine's role as Star Keeper will be performed by understudy Peter Bodenham for "foreseeable" performances, Opera North said.