Author J.K. Rowling says that the Harry Potter spin-off movie franchise Fantastic Beasts and Where to Find Them will consist of five movies, up from the already announced three films.

Rowling was speaking to fans at a live event broadcast in movie theatres around the world ahead of the November release of the first Fantastic Beasts movie.

"I can confirm it will be five new movies," she said.

The movies will be released by Hollywood studio Warner Bros.