LONDON - The producers of James Bond films have acknowledged that an early version of the screenplay for the new movie "SPECTRE" was among the material stolen in the massive cyberattack on Sony Pictures Entertainment.

The producers said in a statement Saturday that they are concerned that third parties who received the screenplay might seek to publish it - and warned the material is subject to copyright protection around the world.

The producers promised to "take all necessary steps to protect their rights against the persons who stole the screenplay, and against anyone who makes infringing uses of it or attempts to take commercial advantage of confidential property it knows to be stolen."

The warning was issued by EON productions, the U.K. affiliate of Danjaq LLC, the U.S.-based company that co-owns, with Metro-Goldwyn-Mayer Studios, the copyright to the Bond films and their merchandising.

There's been speculation that North Korea is behind the cyberattack in retaliation for the upcoming comedy "The Interview." That film depicts an assassination attempt on North Korean leader Kim Jong Un. North Korea has condemned the film, but denied the hack.

The revelation is just the latest among the spectacular leaks that are causing continuing embarrassment for Sony.

Highly sensitive material is being leaked almost daily, including an exchange between Oscar-winning producer Scott Rudin and Sony Pictures Entertainment co-chairman, Amy Pascal. Rudin called Angelina Jolie a "spoiled brat" and made racially offensive jokes about President Barack Obama's presumed taste in movies.

Rudin and Pascal have apologized.

The next 007 adventure, - called "SPECTRE," after the dastardly fictional terrorist organization featured in "Dr. No" - is so hotly anticipated that even the revelation of its title was a media event. It will be Daniel Craig's fourth film as Bond.