Evans is lining up a Hollywood actress to play the late British royal - who tragically died in a car crash in August 1997 - in a film that will be based on her bodyguard Ken Wharfe's memoirs from his book 'Diana: Closely Guarded Secret', reported Mirror online.

"We are dealing with about 11 years of her life from just after she had Harry, when he's aged about two, and it's partly from the point of view of her protection bodyguard. The emphasis on this really is authenticity and to discover what she went through. Unless you are a Diana freak, quite a lot of it will be unknown to the audience," said Evans.

"The movie's not saying she is unbelievably wonderful or she's a pain in the neck, the audience can make their own view. I think she had some marvellous qualities, absolutely phenomenal qualities and tremendous charisma. She was also very good at one-liners very witty, sharp.

"Intellectually, she was not in the top level but on the other hand had native cunning, stubbornness. Once she made up her mind she was like a bulldozer. She could be a pain, she was lethal. She utilised friendships and dumped friendships," he added.

Evans is hoping his movie will follow in the successful footsteps of 'The Iron Lady', which saw Meryl Streep play former British Prime Minister Margaret Thatcher, but he says the political film "isn't great".