Marvel is suing former comic-book artists to keep full control over characters including Iron Man, Thor, and Spider-Man

• Marvel is suing ex-comic book artists or their estates to keep full control over several characters.
• It follows complaints from the artists' heirs, according to The Hollywood Reporter.
• Their creations were made "for hire" and Marvel claims that this means it fully owns the rights.

Disney's Marvel division is suing former comic-book artists to keep full control of classic characters.

It filed suit against Larry Lieber, and the estates of Stan Lee, Steve Ditko, Don Heck, Don Rico, and Gene Colan.

The lawsuit, which was viewed by The Hollywood Reporter, claims that Marvel holds full ownership over characters including Iron Man, Spider-Man, and Thor.

The development came after the artists' relatives sent termination notices to try and reclaim part of the rights to several characters.

The artists all co-created the characters in question between the 1950s and 1970s. Their creations, however, were made when they were working on a "for hire," basis.

This arrangement means the artists cannot reclaim rights to them under the Copyright Act, Marvel argued in the filing.

In reference to Lieber, who is Lee's brother, Marvel said in the lawsuit: "Marvel assigned Lieber stories to write, had the right to exercise creative control over Lieber's contributions, and paid Lieber a per-page rate for his contributions."

Marc Toberoff, who represents the artists, the lawsuits were based on "an anachronistic and highly criticized interpretation of 'work-made-for-hire' under the 1909 Copyright Act that needs to be rectified," Reuters reported.

But Marvel attorney, Dan Petrocelli told Reuters in a statement: "Since these were works made for hire and thus owned by Marvel, we filed these lawsuits to confirm that the termination notices are invalid and of no legal effect."

This is not the only recent legal battle that Marvel and Disney have been involved in. "Black Widow" actor Scarlett Johansson is suing Disney over the movie's dual-release. The lawsuit argues that Disney violated her contract by debuting the film online and in theaters.

According to court documents shared with Insider, Johansson's representatives contacted Marvel to ensure that the movie would solely be released in theatres.