LONDON (AFP) - The script of a new Harry Potter play is to be published following its world premiere in London in July, publishers announced on Wednesday.

Harry Potter And The Cursed Child will officially open in the West End on July 30, while the script will come out on the following day.

The play tells the story of Harry Potter 19 years after the last book, Harry Potter And The Deathly Hallows. He is now married with three children and works at the Ministry of Magic.

"While Harry grapples with a past that refuses to stay where it belongs, his youngest son Albus must struggle with the weight of a family legacy he never wanted," said the official synopsis on publisher Little, Brown's website.

The play is based on an original story by Potter author J.K. Rowling and written by Jack Thorne.

Little, Brown chief executive David Shelley said the firm was "thrilled" to be publishing the script.

"J.K. Rowling and her team have received a huge number of appeals from fans who can't be in London to see the play and who would like to read the play in book format - and so we are absolutely delighted to be able to make it available for them," he added.

The Harry Potter books are one of the world's biggest literary success stories, with more than 450 million copies sold worldwide.

The film versions were also record-breaking, making more than US$7 billion (S$9.7 billion) at the box office.