Part 1" has been leaked online (Jaap Buitendijk/Warner Bros Pictures)

The leak today came after the film's New York City premiere on Monday night, where the stars of the film turned up to promote the first part of the final installment. 

Speculation as to why the leaked clip is only 36 minutes long is suggesting that Warner Brothers feared a leak, and therefore limited the duration of screeners. 

TorrentFreak reports that last year, "Harry Potter And the Half-Blood Prince" was in their "Most Pirated Movies" list for 2009. Mashable claims that a quick search on popular torrent sites has revealed hundreds of links, as eager Potter fans try to get a glimpse ahead of the film's release on Friday. 

The last film of this magnitude to have leaked was "Wolverine", and it didn't have an impact on the film's box office takings. In a similar manner, it is highly unlikely that the leak of the first part of "Harry Potter 7" will affect the film's box office earnings this weekend - with Pottermania a global phenomenon, and with only 36 minutes available online, chances are, it'll only serve to whet the appetites of hungry Potter fans. 

Warner Bros. Entertainment, however, is not taking the matter lightly.

"Last night a portion of `Harry Potter and the Deathly Hallows—Part 1’ was stolen and illegally posted on the internet," the studio said. "This constitutes a serious breach of copyright violation and theft of Warner Bros. property.  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."