The Oscar-winning actor would fill the role for which Tarantino previously wanted Men in Black III star Will Smith, according to Showbiz 411. Idris Elba has been rumoured for the part as well.
Leonardo DiCaprio has also officially joined the film, according to the site. It was reported last week that the Departed actor was in talks for the role of the villainous plantation owner Calvin Candie.
X-Men: First Class actor Michael Fassbender announced last week via Twitter that he had joined the cast of the movie as well, though the post was quickly taken down.
"Great news everyone. Quentin Tarantino has asked me to be his latest film Django Unchained. He was talking so fast, but I said 'f***, yes'," Fassbender wrote.
Shortly after, he continued: "Wait, forget I told you about the Tarantino thing, I wasn't supposed to! F***. My cue to log off."
Fassbender's casting currently remains unconfirmed.
Django Unchained revolves around Django, an escaped slave who teams up with a German bounty hunter to free his wife from slavery and get revenge on his former master.
Django Unchained is scheduled for a 2013 release.