Filmmakers behind a new Michael Jackson documentary have stepped up their legal battle against the King of Pop's estate executors in a bid to clear the way for the movie's release.

Director Craig Williams was recently slapped with a cease-and-desist notice over the rights to footage in Michael Jackson: The Last Photo Shoot, which features clips he shot of the superstar at the Brooklyn Museum of Art in New York City for Ebony magazine in 2007, two years before his death.

His film also includes interviews with Jackson's friends, photographers and stylists as the superstar prepared for the photo session.

Howard Weitzman, attorney for the Michael Jackson estate, claims the singer never agreed to have his "private moments... publicly and commercially exploited", but Williams hit back with his own lawsuit, insisting he and producers at Noval Williams Films legally obtained the rights after the Jackson family passed on the opportunity in 2011.

Williams and his fellow producers have now filed an injunction against estate bosses in New York's Manhattan Supreme Court, compelling them to respond to the suit within 21 days to speed up the process, according to the New York Post.

Williams is seeking declaratory relief that his film isn't infringing copyrights so they can press ahead with the film's sale and release.