JK Rowling has defended the decision to cast a South Korean actress as Voldemort's snake Nagini in 'Fantastic Beasts: Crimes of Grindelwald'.

JK Rowling

JK Rowling

A recent teaser of the upcoming movie showed Claudia Kim turning from a woman into a snake, but the casting has prompted complaints from some fans.

JK - whose film series has been criticised for its lack of representation of non-white actors and actresses - responded to the complaints on Twitter, saying: "The Naga are snake-like mythical creatures of Indonesian mythology, hence the name 'Nagini.' They are sometimes depicted as winged, sometimes as half-human, half-snake. Indonesia comprises a few hundred ethnic groups, including Javanese, Chinese and Betawi. Have a lovely day [snake emoji] (sic)"

The upcoming movie stars the likes of Johnny Depp, Eddie Redmayne and Jude Law.

And 'Fantastic Beasts' producer David Heyman recently hailed Johnny, saying he's an "extraordinary" actor.

He said: "We wanted someone who was extraordinary, who was a little bit off-centre, who had the charisma and the power to [match up to] the wonderful adversary [we had with] Ralph Fiennes. Voldemort was someone who was pure - you know, he knew no love, and he only knew hate. Grindelwald is a different beast.

"There's something about Grindelwald - he's a seducer - and he has no problem wielding his wand, as it were."

Meanwhile, director David Yates has praised Jude's portrayal of Dumbledore.

He said: "We're seeing Dumbledore as a young man, and Dumbledore as a young man's quite a rebel.

"He's a wonderful manipulator, and he has this incredible ability to sort of manoeuvre people into situations that they may not want to be manoeuvred into. And Jude brings this amazing freshness and sexiness and sensuality and sort of wit and sort of charisma to the role."