'See How They Run' director says he was careful to avoid spoiling 'The Mousetrap' (exclusive)

Watch: How see How They Run director avoided spoiling The Mousetrap

See How They Run director Tom George has reassured Agatha Christie fans that he and the team around the movie have been very careful to avoid spoiling Christie's play The Mousetrap.

West End audiences have been told to keep the ending of the murder-mystery play to themselves ever since it was first staged way back in 1952 — making it the longest-running continuous production in history.

George's film, penned by British comedy veteran Mark Chappell, follows police officers played by Sam Rockwell and Saoirse Ronan as they investigate a death at the theatre where the play is being performed.

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The revolving door of suspects spins as it becomes clear that the plans to adapt the story for a Hollywood movie may be a motivation for the murder.

"We were very careful to make sure we weren't revealing their most closely guarded secret, which is their ending," George told Yahoo of the way his movie pays homage to The Mousetrap.

He added: "Although it's rooted in many ways and the plot centres around The Mousetrap, I think the film's connections and references go beyond that into murder-mysteries more generally, but also into the world of cinema and the differences between Hollywood and European cinema and film noir."

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George, who previously helmed award-winning sitcom This Country, said he hopes the references to whodunnits of the past "adds to the richness" of See How They Run.

He said that he was very aware of the secrecy around The Mousetrap, which even extended to Christie's family criticising Wikipedia for revealing the ending.

George said: "[The Christie estate] read the script and could see, I hope, that it was all intended with affection and that was the place we were coming from with it."

The movie features an enormous ensemble cast drawn from American cinema and the big and small screens in Britain, from Adrien Brody and David Oyelowo to Sian Clifford and Reece Shearsmith.

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George's former This Country co-lead Charlie Cooper also has a small role as an usher at the theatre.

"It wasn't really a case of thinking about whether we should have a film actor or a British comic for each part," said the filmmaker.

He added: "I'm a firm believer that good comic actors and good actors in general can work across both mediums.

"It's just satisfying to see that the ensemble has come together in what feels like a satisfying whole. They all belong in that world together."

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George said he hopes to be able to preserve the secrets of his own story via viewers like him, with the director saying he is "the last to pick the twist" when he watches a whodunnit.

See How They Run is due to be released into UK cinemas on 9 September.

Watch: Trailer for whodunnit thriller See How They Run