Warner Brothers said Thursday it was "working actively" to remove a section of the latest Harry Potter movie which has been "stolen" and illegally posted online, even before the film opens.
The studio giant said it would vigorously pursue those who posted the reportedly 36-minute clip of the movie's start on the Internet, a week after the world premiere "Harry Potter and the Deathly Hallows: Part One"
The movie, expected to be a global blockbuster like previous instalments of the boy wizard's adventures, doesn't hit screens in most of the world until Friday, November 19.
"This week a portion of 'Harry Potter and the Deathly Hallows: Part 1' was stolen and illegally posted on the Internet. This constitutes a serious breach of copyright violation and theft of Warner Bros. property," it said.
"We are working actively to restrict and/or remove copies that may be available. Also, we are vigorously investigating this matter and will prosecute those involved to the full extent of the law," added a statement.
Britain's New Musical Express (NME) reported that the stolen section was the first 36 minutes of the movie. Warner Bros could not immediately confirm the length of the clip.
In "Harry Potter and the Deathly Hallows: Part One," Voldemort and his evil henchmen control huge swathes of the wizarding world and Harry is constantly in danger.
Harry, Hermione and Ron leave behind the safety of school and their families and set out alone to seek out horcruxes, items in which Voldemort has hidden pieces of his soul, so they can destroy them and ultimately bring him down.
Much of the film revolves around a road trip, as the trio travel around Britain to try to stay safe, and focuses on the close friendship between the main characters, in particular the budding romance between Hermione and Ron.
It ends on a cliffhanger, however, as the final resolution will not be known until Part Two, which is due out in July. That will cover a final, explosive battle between Potter and his allies and Voldemort's dark forces.
Explore further: When a selfie is not enough: India abuzz over 'velfie' craze