Nicole Kidman thinks 'The Killing of a Sacred Deer' is the strangest film she has worked on.

Nicole Kidman

Nicole Kidman

The 50-year-old actress admits she wondered "every day" how they were going to make the film work but praised director Yorgos Lanthimos for guiding her and her co-star Colin Farrell through it.

She said: "I would go in every day going, 'I wonder how we're going to play this or make this work.' ...

"I was like, 'Yorgos, I have no idea how to play this as a comedy.' [And Colin Farrell said] 'This will be like nothing you've ever experienced.'"

'The Killing of a Sacred Deer' follows the story of a surgeon who has been accused of killing a patient on the operating table. But he has to make a big sacrifice when the behaviour of a teenage boy, who he has taken under his wing, starts to turn sinister.

In one scene, Steven the surgeon has sex with his wife Anna, played by Kidman, where she pretends to be a patient on anaesthetic, and Kidman admits she found that scene "really strange" but felt it was important to do it as it showed so much about the couple's relationship.

She added: "That scene is really strange and says so much about the relationship. I was at first going, 'Oh, no, I don't want to have to do that,' but I also relished the idea because it was so unique and compelling."

And Nicole is thrilled with how her career is going.

She told USA Today: "Work ebbs and flows. Is it lovely for it to collide with turning 50? Yes, and to be able to have 'Big Little Lies' embraced like it was - particularly at this time for women - speaks loudly to the community."