Robert Downey Jr., left, and his wife Susan arrive at the American Film Institute Life Achievement Award dinner honouring Warren Beatty in Los Angeles in June.Robert Downey Jr., left, and his wife Susan arrive at the American Film Institute Life Achievement Award dinner honouring Warren Beatty in Los Angeles in June. (Matt Sayles/Associated Press)

After successfully playing Iron Man, actor Robert Downey Jr. is set to play another famous hero — Sherlock Holmes.

Downey, who earned raves for the action blockbuster hit Iron Man this spring, has signed on to play the iconic literary sleuth in an upcoming film directed by British filmmaker Guy Ritchie, Warner Bros. announced on Thursday.

Ritchie is best known for his action-packed crime capers including Snatch and Lock, Stock and Two Smoking Barrels.

Shooting on the film — touted as a reimagined, adventure-oriented portrait of author Arthur Conan Doyle's brilliant detective — is slated to begin in October. It is scheduled to hit theatres in 2010.

The project is based on a forthcoming Holmes comic book by Lionel Wigram, who is also a producer on the film adaptation. Other producers include Joel Silver and Susan Downey, who is married to Robert Downey Jr.

A comedic take on the deerstalker cap-wearing, pipe-smoking detective is also in the works, with Sacha Baron Cohen to star as Holmes and Will Ferrell to portray sidekick Dr. Watson.

With files from the Associated Press