JK Rowling launches 'Harry Potter and the Cursed Child'

JK Rowling thanked fans for 'keeping the secrets' of the new Harry Potter stage play at its gala opening today in the West End.

Speaking to ITV News London, the author said it felt "extraordinary" to officially launch the play after three years of hard work behind the scenes.

She said the decision to take the wildly popular book franchise onto the stage was "daunting".

"I've probably had three offers a week to turn it into a play, a musical, an ice show... but it's only when I met Sonia Friedman (the play's producer) that I thought 'this is the one," she said.

The play is set 19 years after the events of the last book, and follows Harry, now grown up, as an overworked employee of the Ministry of Magic.

Harry and his wife Ginny Weasley wave off their youngest son Albus Severus to their old wizarding school, Hogwarts - but once there, Albus struggles with the weight of his family legacy and goes to extreme lengths to right the wrongs of the past.

The two-part play stretches over five hours and was co-devised by Rowling, written by Jack Thorne and directed by John Tiffany.

Previews have garnered a host of five star reviews from critics.

Celebrity Potter fans were out in force at the premiere - including comedians Frank Skinner and David Baddiel, and even London's Mayor Sadiq Khan.

The Cursed Child is currently sold out, but another 250,000 tickets are set to go on sale next week as the play's run has been extended until December 2017.

Today's opening is also followed by the midnight release of the play's script, so fans can find out what happens next to the boy wizard and his friends.