Sienna Miller is going to star Guy Ritchie's new movie, 'Sherlock Holmes.'
Meanwhile, Miller is now shooting Ridley Scott's Robin Hood movie 'Nottingham.'
Ritchie also wants to take Russell Crowe and Sam Riley from the same set to play in his new detective film.
Miller will co-star with Robert Downey Jr. in Ritchie's film. Filming will start next month and the movie is due for 2010 release.
Source: Malaysia Sun