Rachel McAdams is to star in ‘Sherlock Holmes’.

The ‘Mean Girls’ actress is set to play Irene Adler, the love interest of the fictional titular detective of the film’s name, who will be portrayed by ‘Iron Man’ star Robert Downey Jr.

‘Alfie’ actor Jude Law is also appearing in the Guy Ritchie movie as Holmes’ sidekick Doctor Watson.

It is also being reported plans for a sequel to the film - which is set to start shooting next month - are already underway.

Rachel’s character appears in just one of Sir Arthur Conan Doyle’s stories about the detective, ‘A Scandal in Bohemia’. There is no physical contact between the pair in the story, but it states that Holmes is impressed by her intelligence.

Image WENN