(Reuters) - The estate of one of Superman's co-creators has filed a copyright lawsuit in a U.S. court against Warner Bros. Discovery ( WBD ) ahead of the release of its new movie "Superman," part of a planned reboot of the DC Comics superhero film franchise.

The lawsuit was filed on Friday in federal court in New York City by the estate of Superman illustrator Joseph Shuster, who created the famous superhero along with writer Jerome Siegel. 

The lawsuit noted that Shuster and Siegel had licensed their rights to the character to Detective Comics, the predecessor of DC Comics, now a subsidiary of Warner. The lawsuit claims that under British law Shuster's rights reverted to his estate in 2017, 25 years after his death. The estate accused Warner of unlawfully failing to pay royalties to use Superman in Britain, Canada, Australia and other countries outside the United States.

The new Superman movie, directed by James Gunn and starring David Corenswet, is set to be released in theaters in July. The new litigation could complicate the international distribution of the film. It marks the latest salvo in a long-running legal battle over the rights to the character. 

Shuster's estate is seeking monetary damages and a court order blocking Warner from depicting Superman without a license.

"We fundamentally disagree with the merits of the lawsuit, and will vigorously defend our rights," a Warner spokesperson said. 

The estate's attorney did not immediately respond to a request for comment.

The lawsuit said Shuster and Siegel began creating Superman comic strips in 1934. DC's predecessor Detective Comics began publishing their comics in 1938.

Shuster and Siegel and their estates have been involved in litigation with Warner over the rights to Superman for decades. The San Francisco-based 9th U.S. Circuit Court of Appeals determined in 2013 that the creators could not reclaim their rights from Warner under U.S. law.

The new lawsuit, however, cites British law. The estate claimed that the distribution of works featuring Superman since 2017 - including movies, television shows and video games - infringes its copyright in countries that follow British law.