Robert Harris’ Conclave was published in 2016 and the film adaptation, starring Ralph Fiennes, Stanley Tucci, John Lithgow, Sergio Castellitto and Isabella Rossellini, was released last year.

Made by German director Edward Berger, it picked up four awards, including best film and best British film, at the Royal Festival Hall on Sunday.

Harris, who lives near Hungerford, West Berkshire, said he was writing another book when Pope Francis’ election in 2013 caught his imagination.

A former political journalist, he said he wrote Conclave without any expectation that it would be dramatised – and that doing so would be “fatal”.

He said any author turning up to a film adaptation is likely to be treated like a “drunken old uncle” but that Conclave’s makers were “very nice” and that he had a “terrific” experience.

“It’s a great thing because it’s a very quiet, anonymous life being a writer,” Harris told BBC Radio 4’s Today.

“Then every so often, when you get pitched into this showbiz world and emerge blinking into the light, it’s great. The whole experience has been terrific.

“It’s a very good film. I can say that dispassionately. I have had a few things made [from his work] that have not been that good and this one is really good!”

Asked by host Nick Robinson if he would write a book about the Church of England, he said he had been attracted to the intrigue and processes of the Catholic church.

“It’s not quite got the oomph, has it, of the Vatican? Lambeth Palace is a very pleasant place but it’s not exactly like St Peter’s Basilica. There’s something about the ancient rituals of the Catholic church.

“The Sistine Chapel was built for the election of a pope, that’s what it’s there for. They’re locked in. It’s also got a sort of Agatha Christie-like room dynamic.”

Conclave also won awards for adapted screenplay and editing.