Artists Ben and Ray Lai allege the iconic red costume, worn by Robert Downey, Jr. in three Iron Man films and two Avengers movies, is based on drawings published in their 2001 Radix comic book.

In the legal papers, the brothers suggest that the original 1963 comic book Iron Man sported a Spandex outfit, but in Jon Favreau's 2008 movie adaptation, the superhero wears a "futuristic, armoured, and weaponised" costume similar to that in their drawings.

The Lai brothers are demanding a share of the Iron Man profits, according to