J K Rowling will write a new film based on Fantastic Beasts and Where to Find Them, one of her Comic Relief Harry Potter universe titles.
The author will write the script for the Warner Brothers film, billed as the first in a new series.
The book is a guide to wizarding creatures by "Newt Scamander", written by Rowling and published by Bloomsbury in aid of Comic Relief in 2001.
Rowling said: "It all started when Warner Bros. came to me with the suggestion of turning Fantastic Beasts and Where to Find Them into a film. I thought it was a fun idea, but the idea of seeing Newt Scamander, the supposed author of Fantastic Beasts, realised by another writer was difficult. Having lived for so long in my fictional universe, I feel very protective of it and I already knew a lot about Newt…
"As I considered Warners’ proposal, an idea took shape that I couldn’t dislodge. That is how I ended up pitching my own idea for a film to Warner Bros."
The bestselling writer said the film would not be a prequel or a sequel to the Harry Potter series, but instead would be "an extension of the wizarding world".
She added: "The laws and customs of the hidden magical society will be familiar to anyone who has read the Harry Potter books or seen the films, but Newt’s story will start in New York, seventy years before Harry’s gets underway."
Kevin Tsujihara, c.e.o. of Warner Bros. Entertainment said: "She is an extraordinary writer, who ignited a reading revolution around the world, which then became an unprecedented film phenomenon. We know that audiences will be as excited as we are to see what her brilliant and boundless imagination conjures up for us."
Warner Bros said that addition to the film, Fantastic Beats would also be developed across computer games, consumer products and digital businesses.
The company also announced it would serve as the worldwide TV distributor outside of the UK for the BBC adaptation of The Casual Vacancy, being produced next year.