Sienna Miller rumored for Guy Ritchie's 'Sherlock Holmes'

Sienna Miller is to star in Guy Ritchie's new film 'Sherlock Holmes'.

The 'Edge of Love' actress was due to star in as Maid Marion in Ridley Scott's movie 'Nottingham' - a retelling of the story of legendary English thief Robin Hood - but was able to commit to Guy's film after the project was put on hold.

The filming of 'Nottingham' has been delayed because Ridley is keen for scenes shot in Sherwood Forest to include trees with green leaves, meaning shooting has to wait until next year.

'Sherlock Holmes' filming starts next month, with Robert Downey Jr. set to play the fictional British detective.

Guy has already promised his version of Holmes will be much "riskier" than previous portrayals and the film will "take advantage of Holmes' skills as a boxer and swordsman".

Sienna isn't the only 'Nottingham' star to be linked to 'Sherlock Holmes'.

Russell Crowe - who had agreed to play the Sheriff of Nottingham - was reported to be the hot favourite to play Holmes' sidekick Dr. Watson.

However, this week Guy dismissed the rumours, saying: "Somebody just told me I have Russell Crowe lined up but that's news to me. I suspect that hasn't happened and I'm still looking for my Watson."

Guy also revealed Robert can't wait to start shooting the movie.

He added: "Robert is pretty excited. He's going to get here in the middle of the month and he's raring to get going.

"Sherlock Holmes is a bad a*s in this movie alright."