Batman's sidekick Robin is set for a sex change in the upcoming Batman V. Superman: Dawn of Justice movie, according to online reports.

The Hunger Games: Catching Fire star Jena Malone has been cast in the pivotal role, according to a set insider, who has risked a huge fine from Warner Bros. executives for revealing the details to a Michigan Tv news network.

The blockbuster, featuring Henry Cavill as Superman and Ben Affleck as Batman, is filming in Detroit and Malone has reportedly been spotted on the set.

Directed by Zack Snyder, the Man of Steel sequel will also feature Gal Gadot as Wonder Woman, Jason Momoa as Aquaman and Jesse Eisenberg as villain Lex Luthor, while Amy Adams, Laurence Fishburne and Diane Lane will reprise their characters.