Image copyright Warner Bros Image caption In the trailer Claudia Kim transforms into a snake

JK Rowling has defended the casting of a Korean actress as Voldemort's snake Nagini in the Fantastic Beasts sequel.

The latest trailer has revealed Claudia Kim as Nagini and sees her transform into a snake.

Some have criticised the fact the only Asian actor in the cast plays a reptile that is a villain's slave.

But JK Rowling tweeted that Nagini is based on "the Naga", which are "snake-like mythical creatures of Indonesian mythology."

She added: "They are sometimes depicted as winged, sometimes as half-human, half-snake. Indonesia comprises a few hundred ethnic groups, including Javanese, Chinese and Betawi."

Rowling has been criticised in the past for the lack of diversity in her Harry Potter books and one fan accused her of the casting of Nagini as an Asian woman as an afterthought to try and increase representation.

Another fan felt it played into the representation of Asian people as "peripheral in a white-centric world" and "Asian women exist to mainly serve white men's interests."

Rowling, who is a producer on Fantastic Beasts: The Crimes of Grindelwald, intimated the casting had not been an afterthought.

She said she had been keeping the fact that Nagini was really a Maledictus - a female who had been turned into a beast due to a curse - a secret for twenty years.

Image copyright Courtesy of Warner Bros. Pictures Image caption Jude Law plays young Albus Dumbledore in the film alongside Ezra Miller as Credence and Claudia Kim as Nagini

The Fantastic Beasts sequel has already caused controversy for its casting of Johnny Depp as Grindelwald, after he was accused of domestic abuse - claims he denied.

JK Rowling said she was "happy" about his casting.

The film will also feature Jude Law as young Dumbledore. JK Rowling has said in the past that Dumbledore is gay but the film's director David Yates has upset some fans by saying that he will not be "explicitly" gay in the new film.

Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk.