Thompson on Hollywood confirmed that Tarantino has already handed a first draft of the screenplay to The Weinstein Company, and has renamed the film Django Unchained.
The project will see Tarantino reunited with Pulp Fiction collaborator Stacey Sher, as well as his Inglourious Basterds star Christoph Waltz, who won an Academy Award for his role as the villainous Colonel Hans Landa.
Hollywood Elsewhere, who claim to have acquired a copy of the draft, have revealed that the film will follow the story of a freed slave called Django who joins up with a German mercenary, played by Waltz, in order to free his wife from a plantation slaver.
Other actors rumoured to be under consideration for parts in the film include the likes of Keith Carradine, Treat Williams and Franco Nero.
Uma Thurman recently confirmed that Tarantino was working on a Western - called The Southern at the time - that had pushed back work on their proposed follow-up to Kill Bill Vol. 2.
Django Unchained is set to enter production later this year.