An investigation into how a copy of the long-awaited sequel to J M Barrie's children's classic Peter Pan was leaked to a newspaper in the US is under way.
Geraldine McCaughrean is a well-known children's author
The book, called Peter Pan in Scarlet and written by author Geraldine McCaughrean, is due out on 5 October.
But the New York Times published a summary of the plot on Tuesday.
London's Great Ormond Street Hospital - which owns the copyright - and Oxford University Press said they are looking into how the manuscript was leaked.
In its article, the New York Times revealed that Peter Pan in Scarlet is set in 1926 - more than 20 years after Barrie's play was first produced on the London stage.
The highly-anticipated book has been shrouded in secrecy, with publishers imposing a pre-publication embargo.
Great Ormond Street Hospital and Oxford University Press said that while the article contained details that only someone who had read the manuscript could know, it also had some inaccuracies.
"Obviously we will be trying to find out, in conjunction with the US publisher [Simon and Schuster] of Peter Pan in Scarlet, how this has happened," a joint statement said.
"However, as the published article only included a few new details, plus some inaccuracies, we do not feel that the secrecy around the manuscript has been compromised.
"We are delighted with the interest that publication of Peter Pan in Scarlet has generated and look forward very much to 5 October when so much more will be revealed."
When Barrie died in 1937, he left the copyright and other intellectual property rights of Peter Pan to Great Ormond Street Hospital.
Royalties from the new book will be split between the author and the hospital.
McCaughrean, 55, who has promised readers "high adventure, and swashbuckling danger", was chosen by the hospital to write the sequel after a worldwide search.
She has previously won the Whitbread Children's Book of the Year three times for re-interpreting classics such as Noah's Ark, Moby Dick and The Canterbury Tales for younger readers.