Australian film star Nicole Kidman has described 2014 as her toughest ever year, saying the sudden death of her father in Singapore had left her family in "so much pain".

In Sydney for the premiere of her new movie "Paddington", the Oscar winner said her close-knit family were "hunkering down for Christmas" without her father Antony Kidman.

"You know, I will look back at this year as one of the toughest years our family's ever gone through -- I mean, the toughest ever," she told Sydney's Daily Telegraph Monday.

Antony Kidman, a doctor, died in Singapore in September from a heart attack as he was visiting daughter Antonia and her family.

"I talk about it because I like to keep him alive, in a way," his famous older daughter said. "Even though you talk about it, you're still in so much pain so, yeah, as a family we're still in a lot of pain.

"As any family knows when you've had a huge loss, it makes you tighter, you have to also protect each other," she added.

Kidman has also had a bumpy year on-screen, with the thriller "Before I Go to Sleep" last month her worst ever large scale opening, taking just over US$2 million after a wide release across 1,935 theatres.

In that movie, Kidman plays a woman suffering from chronic amnesia who wakes up every morning with no recollection of her life from her early 20s onwards.

Its weak opening marked another disappointing flop for Kidman after "Grace of Monaco," which was booed at the Cannes festival earlier this year and savaged by critics.

Kidman said she chose to make the movie "Paddington" because she wanted something her daughters with singer Keith Urban -- Sunday, six, and Faith, three -- could enjoy.

"There's nothing like sitting in the premiere of a kids' film, where you hear them all laughing," she said.