Director James Cameron is facing a copyright infringement lawsuit from a man who claims the legendary moviemaker stole his idea for Avatar.

Eric Ryder filed a lawsuit at Los Angeles County Superior Court on Thursday, claiming he approached Cameron's production company Lightstorm Entertainment in 1999 with an idea for an "environmentally themed 3D epic about a corporation's colonization and plundering of a distant moon's lush and wondrous natural setting."

He also claims his project included "self-contained robotic exterior suits which house a single human operator... just like in Avatar."

The papers suggest Cameron's company officials turned their backs on talks in 2002, and that Ryder complained to the director's representatives in 2009, when the movie became the highest-grossing film of all time.

Ryder is seeking unspecified damages and wants to be awarded a portion of the film's profits.