J.K. Rowling has written a ''wonderful script'' for the Harry Potter spin-off 'Fantastic Beasts and Where to Find Them'.

The 49-year-old author's latest offering - which is set in New York, 70 years before Harry and his wizard friends arrive at Hogwarts school - is said to be in its ''early stages'', with filming set to begin next year.

The plot follows explorer Newt Scamander as he travels the world before penning the titular textbook 'Fantastic Beasts and Where to Find Them' - which Harry later studies during his time at the wizarding school.

The franchise's producer David Heyman has once again teamed up with director David Yates, who helmed the final four Potter movies in the series, and confessed he is ''really excited'' about the project.

Speaking at the London premiere of his latest movie 'Paddington' yesterday (23.11.14), he said: ''Jo [Rowling] has written a wonderful script.

''It's early stages. David Yates is directing and we start filming next year. I'm just really excited about it.''

Heyman previously described working with Rowling on the spin-off - which is expected to be made into ''at least'' a trilogy - as a ''joy''.

He said: ''She is so smart, and her turn of phrase, the precision of the language she uses, is a joy to behold.''

'Fantastic Beasts and Where to Find Them' is set to hit cinemas in November 2016.