He added: “But there were a couple of days which he was not available, so he sent a couple of his friends, who happened to be part of the Royal household. It was amazing.

 Kevin Doyle revealed the butlers were 'terribly helpful'
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Kevin Doyle revealed the butlers were 'terribly helpful'Credit: Getty Images - Getty
 The Queen's butlers helped the cast on set at Highclere Castle in Hampshire
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The Queen's butlers helped the cast on set at Highclere Castle in HampshireCredit: Getty - Contributor
 Film bosses wanted to make sure the movie was completely accurate
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Film bosses wanted to make sure the movie was completely accurateCredit: Handout

“They were able to help us specifically with how a King and Queen are treated differently to normal members of the aristocracy. They were terribly helpful. ”

However, the two men remained tight lipped when it came to spilling the beans on the real royals.

“No, they were very careful and very discreet,” the star said.

Earlier this week, stars from the movie flocked to London's Leicester Square for the world premiere of the highly-anticipated film.

 The highly anticipated movie will hit UK cinemas this Friday
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The highly anticipated movie will hit UK cinemas this FridayCredit: PA:Press Association
 Earlier this week, cast of the film attended the premiere
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Earlier this week, cast of the film attended the premiereCredit: Splash News