Downey Jr. is to play Victorian super sleuth Sherlock Holmes in an upcoming blockbuster that studio Warner Bros, also behind the hit Harry Potter series, hopes will become a lucrative franchise.
The 43-year-old said one reason he was chosen for the role may have been his involvement in action movie "Iron Man", which earned over $570 million in global ticket sales this year, and he promised his Holmes would be the best screen portrayal ever.