Naomi Watts shares the same cheeky sense of humour as Princess Diana.

The actress - who plays the late Princess of Wales in new biopic 'Diana' - enjoys telling salubrious jokes to entertain her co-stars on set, much like the People's Princess, who tragically died in a car crash in Paris in 1997.

Director Oliver Hirschbiegel quipped: ''Regarding similarities between Naomi and Diana - they both like to tell dirty jokes!''

A bashful Naomi blushed: ''Yes, why not? A good dirty joke, every now and then. Early in the morning, [on set] before conquering the day! Diana used to do that too, that's true.''

The 44-year-old star's new film - which focuses on the last two years of the British royal's life and her romance with heart surgeon Dr. Hasnat Khan - has been ripped to shreds by critics in the Diana's native Britain, and Naomi has avoiding reading the reviews because she worries it would destroy her confidence.

Quizzed about the movie's reception, she acknowledged: ''I didn't really follow the reactions. I don't think that would be a good idea for me ... We always knew the response would be extreme in England.

''The opinion has always been divided there about Diana. It's definitely a sensitive subject, the English feel like she belongs to them...''

Nevertheless, the Australian-born beauty hopes people will be able to identify with aspects of her portrayal of Diana - the mother of Prince William and Prince Harry - and not concentrate on the differences between them.

She told France's Voici magazine: ''It's the very definition of an icon. Everyone has their own ways of identifying with 'larger than life' public figures. If you're a strong and intelligent person, you think 'She's like me!' But if you're feeling fragile at the moment, you'll identify with that side of her.''