Naomi Watts, who plays tragic Princess Diana in her new flick, has admitted the difficulties of re-creating one of last century’s most iconic figures. “Playing Princess Diana was the hardest thing I’ve done,” the Daily Mail quoted her as telling Manhattan magazine. “Because of the pressure of everyone’s beliefs about who she was and the fact that it was just really hard to claim her as my own, since everybody feels they know her,” she said.

The 44-year-old British-born actress said that she wanted to channel the late royal, rather than mimic her.

“I don’t want to get caught up in mimicry - that’s the worst thing,” she said.

“I was to try to embody her and get the essence of her. Those things are really important to me,” she added.

The film, out next year, follows Diana’s love affair with Pakistani heart surgeon Dr Hasnat Khan, played by Lost star Naveen Andrews.