Martin Freeman turned down the chance to play Bilbo Baggins in 'The Hobbit'.
The actor was offered the lead in Peter Jackson's big-screen adaptation of J.R.R. Tolkien's classic novel but declined because he had already signed to 20 weeks filming BBC TV drama 'Sherlock' next year, in which he plays Sherlock Holmes sidekick Dr Watson.
A source said: "It was one of the most difficult decisions of his career, MGM, who are making the film, only got a formal offer over in the last couple of weeks.
"It was too late for Martin because he had already signed up for another series of 'Sherlock'. It was agonising but he had no other choice."
Jackson - who directed the 'Lord of the Rings' trilogy, a follow-up to 'The Hobbit' book - is now holding auditions in London, New York and Sydney in the hope of finding an unknown actor for the role.
The source added to The Sun newspaper: "All the actors had to read four pages of the script to camera which is being shown to Peter Jackson. He is now looking for a hidden gem now Martin has ruled himself out of the job."
'The Hobbit' is set to hit cinema screens in 2012.