AceShowbiz -

Robert Downey Jr. is going to exchange his bullet-proof armor suit with magnifying glass, calabash pipe and and a deerstalker cap. That happens because the "Iron Man" star has been chosen to portray a legendary master detective in Guy Ritchie's feature film project "Sherlock Holmes".

Nailing the titular character part, the 43-year-old actor joins the project after British filmmaker Guy Ritchie allegedly showed him the polished version of the movie's script. In re-imagining Holmes, the leading man of "Zodiac" is expected to display a more adventurous side of the witty detective. Depicting this character will be Downey Jr.'s first job after his highly successful "Iron Man".

Based on Lionel Wigram's upcoming comic book, "Sherlock Holmes" is a drama adventure movie centering on the famous late 19th century detective. It has been scheduled to start its production in October for 2010 release and should not be mistaken with Judd Apatow's Arthur Conan Doyle-inspired movie starring Sacha Baron Cohen and Will Ferrell, "Untitled Sherlock Holmes Project".