Director James Cameron has been ordered to hand over his draft screenplays for Avatar to a former employee who claims the moviemaker stole his idea for the blockbuster.

Eric Ryder, who previously worked for Cameron's Lightstorm Entertainment Inc. production company, filed suit against the Oscar winner in 2011, alleging the highly-successful fantasy film was based on a script he wrote for a movie called K.R.Z. 2068.

Ryder is demanding compensation over claims Cameron used his ideas without permission and without giving him due credit, but the director insists he wrote Avatar five years before his accuser pitched the idea to his production company.

The long-running legal battle went back to court in California this week (beg21Jan13), and Los Angeles Superior Court Judge Alan Rosenfield sided with Ryder by ordering Cameron to turn over the draft screenplays he wrote for Avatar.

The writer and his legal team have also been granted access to back-up discs from computers used by the Titanic director, but the judge denied Ryder's request to see the new screenplays written for Cameron's upcoming Avatar sequels.

Ryder is seeking unspecified damages for copyright infringement and wants to be awarded a portion of the profits from the film, which grossed more than $2 billion at the global box office following its release in 2009.