Robert Downey Jr's Ritchie fight
Robert Downey Jr. has been sparring with Guy Ritchie while filming 'Sherlock Holmes 2'.
The US actor and the director are said to be about halfway through filming the sequel to their 2009 film about the legendary fictional British detective in London, and between takes they've been getting physically aggressive with each other at Guy's martial arts gym.
Speaking at the premiere of 'Due Date' in London, Robert told BANG Showbiz: "We've been going to Ultimate Fighting Championships (UFC) matches, and I went to Guy's Ju Jistsu gym, and my wife [Susan] has to watch us like, stop the script rehearsal and start sparring in the car. It's embarrassing."
Robert - who is now sober after quitting drugs and drink in the early part of the last decade - said while he doesn't go out partying, he doesn't stop guy and his co-star Jude Law from enjoying themselves on nights out.
He said: "They can do whatever they want, alls I know is I feel good every single morning!"
Robert also told of how he's not daunted by taking on the role of the iconic detective, who has been portrayed by a number of different and respected actors over the years including Jeremy Bret and Ronald Howard.
He added: "If I thought about that, I guess I could stress myself out, but I think all the folks that I have enjoyed playing Sherlock actors have always had a confidence about it, so I just thought, just do what they did and not worry about how I measure up to anyone else."
Sherlock is not expected for release until 2012.