The crime series is an adaptation of Sussex author Peter James’s bestselling novels set in Brighton.
The first series was one of ITV’s most successful dramas with more than eight million people tuning in to watch.
During an interview on The Argus Podcast, Peter revealed that the Duchess of Cornwall offered to play a dead body in an episode of the show during a visit to set in Shoreham.
Peter said he pitched the idea to Camilla after discovering she had selected several his books for her book club.
“I jokingly said would you like a cameo in the next series,” he said. “And she said, ‘yes, maybe I could be a dead body’.
“I think she might do something. I’m definitely going to drop her a note and say the offer is open.”
Camilla, Duchess of Cornwall, on the set of ITV’s Grace in Shoreham
Peter also revealed that he and his wife Lara also make cameo appearances in the second series of Grace – which is set to be released in March this year.
“Without any spoilers, my wife and I play coppers,” he said.
“The first one, she interviews me on television talking about Henry Solomon, the chief constable who was murdered by a burglar back in 1847.
“Then in another, she and I are both standing on the beach where one of the dead bodies washed up.
“You’ll have to look hard, so you don’t miss us – we’re only on camera for about half a minute.”
Discussing Camilla’s visit to set in November last year, Peter revealed how he had become acquaintances with the Duchess.
“About five, six years ago I got a very excited email from a friend saying, ‘get the Daily Mail, look at page five’, and there was a photograph of the Duchess in her library and there about six Roy Grace books right behind her head,” he said.
“She said Peter James was one of her two favourite writers, so I wrote to her as a thank you. Since then, we had this correspondence where she would write to me after every book – a hand-written letter, always very charming.
“Then she started doing a book club during Covid called the Duchess’s Reading Room, and selected the Roy Grace novels.
“I asked her if she’d like to come to the set and see some of the filming and she said absolutely.”
He told how the pair enjoyed a “surreal” half an hour chat over lunch.
“She was really good fun. It was almost surreal – she and I were sat on two chairs in this bare warehouse with all her entourage around,” he said.
“She had a banana and soup in a thermos flask, and one of her ladies in waiting offered me a sandwich. It was just so natural.”
The full episode of The Argus Podcast featuring Peter James will be available on Spotify and Apple Podcasts on Saturday, January 22.