Helena Bonham Carter discusses 'speaking' to Princess Margaret about The Crown role

Like a lot of actors, particularly when playing a historic figure, Helena Bonham Carter goes to a lot of effort to ensure you encapsulates her roles as perfectly as possible - but is she the first to go as far as to actually converse with the dead?

Because, according to the actress, this is exactly what happened while preparing to replace Vanessa Kirby as Princess Margaret in the award-winning Netflix smash The Crown.

She opened up about the experience while appearing alongside Crown co-star Olivia Colman on The Graham Norton Show on Friday (8 November).

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Asked about the lengths she goes to to research her roles, Bonham Carter said: "I go to ridiculous lengths - I don't think it necessarily is necessary, but I enjoy it!"

Known for not being the most conventional sort, she discussed interacting with the Queen’s sister while visiting a medium.

She explained: "As I was seeing the medium for something else, she said, 'Oh Margaret is here. Does that mean anything?' And I said, 'Yes it does'."

She added: "I had been asked to play her. I hadn't actually said yes at that point.

"I just asked, 'Would you mind if I play you?' And she did say, 'I think you're a better idea than the other actor [up for the role]'."

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Host Norton responded by asking if the spirit felt authentic, considering Bonham Carter had met the princess in real life years before when she was alive.

"I had met her, yes. She had a way of complimenting you and putting you down at the same time. And the fact that she said, 'Yeah, I think you're better [than the other actress]'.

"You never knew where you were with her. Then she came through with another note, which was useful whether the psychic was fantastically intuitive or there really was the ghost of Margaret telling me. I don't know.

"She said, 'Get the smoking right'. I smoked in a particular way and always remember cigarette holder is always as much a weapon for expression as anything else. That was a good note. And she was somebody who was innately dramatic."

The Crown returns to Netflix for a third series on Sunday, November 17 on Netflix.