The 40-year-old – who is a big fan of the series – was asked on live TV by stars of the show, Neil Dudgeon and Nick Hendrix, to appear in an upcoming episode of the detective drama.
Holly's co-star, Phillip Schofield, who was in on the surprise, set up the big reveal, saying: "We had a brief meeting this morning to discuss how we were best to do this and I think we are best to do it right now and for you [Neil and Nick] to tell my friend here what she doesn’t know."
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A bemused Holly replied: "What don’t I know?"
Neil, who plays DCI John Barnaby, then revealed: "We have all had a big talk about who we want to appear on Midsomer and we have decided that we want Holly Willoughby to appear in an episode of Midsomer Murders very soon.
Holly will appear in an upcoming episode of Midsomer Murders
"I have been speaking to people upstairs and they have been speaking to your people, but Holly please I am emboldened here to offer you a role in Midsomer Murders.”
"That’s amazing!" exclaimed a shocked Holly. "Yes! Of course, I say yes. I have seen every single episode since it started way back when. Are you serious?"
"Yeah!" Phillip confirmed. “Oh, guys!” a visibly moved Holly said, clutching her hand to her chest. “We need you on the show, we need you,” weighed in Nick, who plays DS Jamie Winter.
Holly then joked that she probably wouldn't be on screen very long because she's a "terrible" actress. She added: “I mean you are going to have to kill me off really quickly because I am terrible at acting. I don’t know what I am going to do.
Neil Dudgeon and Nick Hendrix surprised Holly on This Morning
"I will just walk through the back of the shot slightly. But I would love nothing more."
Speculating about her role, Nick then said: "I am sure we can kill you or you could be a murderer or something." Meanwhile, Neil said Holly’s role would be "more substantial" than a walk-on cameo.
Holly added: “If you kill me, can I die by eating chocolate because I saw an episode where someone died from eating chocolate and I thought, ‘That is the way to go.'"
Neil said that they would have to come up with something new as that plot had been taken, while Holly confirmed: “Fine, I’m there. Whenever you need me.”
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