Helena Bonham Carter reveals what really happened when she spoke to Princess Margaret's ghost

Helena Bonham Carter is no stranger to playing members of the British Royal Family.

The actress previously acted as The Queen Mother in The King's Speech, alongside Colin Firth.

Now, the 53-year-old is taking on the life of Princess Margaret in Season 3 of The Crown on Netflix - alongside Olivia Colman as her sister, Queen Elizabeth.

However, Carter tells 9Honey it was a chance meeting with Princess Margaret's ghost that convinced her to take on the role.

"I was actually seeing this friend - who is a medium and she does other things - about something else," Carter explained on the red carpet at the World Premiere of The Crown's new season in London.

"And she [the friend] said 'By the way, Princess Margaret is here to talk to you - does she mean anything?' 

"And by then, I hadn't even said 'yes' to the part...so, why not? If she's standing there, why not?"

Carter added it was a tough call playing someone so well-known (and dead) and knowing everyone had an opinion of the Princess, so she thought "why not go to the horse's mouth".

And it seems the colourful Royal was only too happy to help the actress along, giving her advice to take into the role.

"She gave me lots of tips," Carter tells 9Honey.

"I first of all asked if she approved of my casting because I definitely needed her on-side and she said 'yes', preferred me to 'the other option', which I thought was actually a very Princess Margaret remark (the little I was beginning to know of her). Ambivalence, basically - complementing and putting someone down at the same time.

"And then she told me to get the smoking right and to scrub up, that I had to get neater in just my general demeanour."

Carter joined other members of the new season cast on the red carpet at the World Premiere, including Game of Thrones and Outlander star Tobias Menzies, who will take on the role of Prince Philip.

Nailing the voice of the Duke of Edinburgh was key for the actor, so he tells 9Honey: "I just listened to him till I started bleeding from the ears".

"You need to sound like him but it can't be an act of mimicry because that's kind of irritating to listen to as well, so there's a balance to be hit," he added.

The Crown Season Three is available to stream on Netflix from Sunday November 17.