Originally released as one of Harry’s textbooks at Hogwarts School of Wizarding, the author has been persuaded by the head of Warner Bros to adapt the book into a screenplay which she reportedly did in 12 days.
Set over seven novels, the Harry Potter series tell the tale of a young boy named Harry who at the age of 11 discovers he is a wizard and follows his quest to overcome the dark wizard Lord Voldemort.
J.K has previously said that Fantastic Beasts and Where to Find Them, which was released in the middle of writing the Harry Potter series, is an extension of the original books, rather than a prequel or sequel.
It follows a magizoologist named Newt Scamander who lives in New York City.
The project was announced last year, where J.K confirmed her return to the world of Harry and friends.
“I always said that I would only revisit the wizarding world if I had an idea that I was really excited about and this is it," she said.
The film adaptations of the books featured Daniel Radcliffe and Emma Watson, and all eight films are in the top 50 highest grossing films of all time.
Daniel Radcliffe, Emma Watson and Rupert Grint
J.K told the New York Times last week that it was the head of Warner Bros. energy and enthusiasm which convinced her to write the latest script.
“We had one dinner, a follow-up telephone call, and then I got out the rough draft that I'd thought was going to be an interesting bit of memorabilia for my kids and started rewriting”, J.K said, before adding, "When Kevin got the top job, he brought a new energy, which rubbed off. He's a very engaging person, thoughtful and funny."
The author has also released two other titles that are part of the Harry Potter series, Quidditch Through The Ages, and The Tales of Beedle the Bard.