Shooting on the eagerly awaited movie prequel Star Wars: Episode III has finally wrapped - but studio bosses warn the film's a long way off completion.

Director George Lucas imposed tight security measures on the Australian set in an effort to keep the storyline a secret, but producer Rick McCallum insists cinema-goers still have a long wait before discovering how main character Anakin Skywalker turns into the villainous Darth Vader.

He says, "Shooting the film is only a small part of the whole process. George is enthusiastic about getting back to the Ranch and starting the next component.

"This will enable him to start thinking about what he needs to pick up when we shoot in March 2004. For George and I, this is only the mid-way point. We still have eighteen months to get through."