UPDATE: A rep for Pitt says the actor has not joined the cast of Sherlock Holmes.

Brad Pitt has been cast as the villain Moriarty in Guy Ritchie’s Sherlock Holmes.

The Inglourious Basterds actor will play the British detective’s nemesis in the film after studio executives demanded the character – originally omitted from the film – be included in the final cut.

Guy called on Brad for the role- who he also worked with on the crime drama Snatch.

“It’s a huge coup to have Brad joining the cast,” a source tells Britain’s The Daily Mirror. “He has worked for Guy before and said if he could, he would do anything to help out.”

“It was an oversight in the film not to make a bigger deal about Moriarty. He is mentioned as Holmes’ arch enemy, but bosses wanted Guy to make more of him.”

The extra shooting is due to start this week, although Robert Downey Jr., who plays the titular detective and Jude Law, who was cast as his sidekick Doctor Watson, completed their scenes months ago.

“It’s going to be a full-on couple of days, but they might just do it in time.”

The release date for the film has been pushed back to December.