Charlize Theron and Carey Mulligan in running to play Princess Diana

London, Feb 6 (ANI): Charlize Theron and Carey Mulligan have been tipped for the lead role in a 30-million-pound film about Princess Diana, which will be based on the years before her divorce from Prince Charles.

The film to be produced by Stephen Evans, who has scored success with The Iron Lady about former Prime Minister Baroness Thatcher, will be made on the basis of Diana's bodyguard's memoirs.

Evans said he wanted to show the world the truth behind what happened to Diana, who would have turned 51 this year, before her 1996 split from her husband.

It will be told partially from the point of view of Ken Wharfe, who could be played by Ewan McGregor.

Wharfe was trusted to look after her sons Princes William and Harry, who called him 'Uncle Ken', and released a controversial book called 'Diana: Closely Guarded Secret' in 2007.

The British film producer told the Sunday Mirror that the film, due for release in 2013, deals with the 11 years of her life 'just after' she gave birth to Harry.

It will not cover her relationship with Dodi Fayed or conspiracy theories about her death in a Paris car crash in 1997.

"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," the Daily Mail quoted Evans as saying.

"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 asserted.

But the acclaimed producer, who has been working with the late princess's private secretary Commander Patrick Jephson on the film, would not reveal who is his favourite actress for the lead role.

"It's a slightly closed book until we get her. We are looking at one or two relatively unknowns we think could play Diana well, and also one or two very famous people. How do you know when you've found the right person? When you've made the movie. You see, that's the risk," he stated.

His film could be the third Diana biopic to come out in the next two years.

Keira Knightley and Scarlett Johansson are rumoured to star in a Pathe film called 'Diana', while rising American actress Jessica Chastain is set to star in 'Caught in Flight'.

That film will focus on Diana's relationship with heart surgeon Hasnat Khan. (ANI)