Julia Roberts was too "scared" to read the book her new movie is based on.

The 56-year-old actress stars opposite Ethan Hawke in psychological thriller 'Leave the World Behind' and though director Sam Esmail sent her a copy of Rumaan Alam's original novel, she wasn't able to read it after dark because she was so freaked out by the story.

Speaking on 'The Graham Norton Show', she said: “I was sent the book by the director who told me I would love it and to read it as fast as I can, but I just couldn’t because it was scaring me and as soon as it got dark, I had to get away from it. The film is spooky and frightening but so good.”

Former US president Barrack Obama and his wife Michelle have produced the movie through their Higher Ground company and Julia was "very excited" to have them on board.

She said: “They are brilliant people and great human beings who have made the world a better place so when they said they were interested in collaborating on the film through their production company I was very excited.”

Julia became a household name when she played an escort opposite Richard Gere in 'Pretty Woman' and she recalled how it was supposed to be a "much darker film" before Disney got involved with the project.

She said: "It was going to be a much darker film called $3,000.

"Vivian was a drug addict and the movie ended with him leaving her in a side street, throwing the money at her, and driving away.

"I got that part in that movie and felt really proud, but when the production company folded and the film disappeared I was crushed.

"But then Disney picked it up, which seemed so unlikely, and made it funny.”

Watch the full interview on 'The Graham Norton Show', BBC One, on Friday (01.12.23) night. Also available on BBC iPlayer.