Naomi Watts has revealed that the attention surrounding her Princess Diana role has been "scary", Belfast Telegraph reported.

The British-born actress has been taken aback by the level of paparazzi interest during the filming of Caught In Flight, which explores Diana's relationship with heart surgeon Dr Hasnat Khan and her tragic death in August 1997.

"We knew that there would be: I mean, Princess Diana is probably the most famous woman of our time," she told Vulture.

"That level of interest started right from when we began shooting in Croatia, and at first we released a picture in order to see if that would keep the paparazzi at bay, but not so much! It's a little bit scary."

Naomi - who next stars in tsunami drama The Impossible opposite Ewan McGregor - said she tries to move on after filming a role, as intense as it may be.

"I move on. Especially since I'm a mum, there's not enough time and space," she said.

"It's interesting. Everyone says, 'How do you make these choices, why do you choose such intense films?' I don't know! They're just themes that are just interesting to me. There's no calculating: Either the material moves me or it doesn't. I would say that if there are any repetitive themes in my work, it's usually about facing things like life and death or fear, I suppose."