Readers excited that they may own valuable first editions of the first Harry Potter book have been urged to carefully check that they have the genuine item.
Earlier this month it was reported that a first edition of JK Rowling's Harry Potter And The Philosopher's Stone could fetch up to £20,000 at auction.
It was revealed by Bonhams Fine Books and Manuscripts that the edition could be identified by a specific typo, sending Potter fans flying to their bookshelves to check chapter 5.
Just 500 hardback copies were initially printed containing a mistake on page 53, with the repetition of "1 wand" on Harry's school supplies shopping list.
But rare bookseller Peter Harrington warned that owners of the book should not get their hopes up, as the mistake was repeated in later editions which are "relatively common".
A spokesman said they had been "inundated with emails" from people claiming to own valuable copies of the novel.
The bookseller has now issued a guide to identifying a true first edition.
In addition to the error on page 53, the publisher must be listed as Bloomsbury at the bottom of the title page.
The latest date issued in the copyright information must be 1997, the year the novel was first published, and it must have been printed in the UK.
The print line on the copyright page must also read "10 9 8 7 6 5 4 3 2 1´´.
Earlier this month, Bonhams' head of books and manuscripts Matthew Haley said: "As the first book in the series, Harry Potter And The Philosopher's Stone has a special place in the affections of the millions of readers across the world and the proof-reading error about the wand in the first edition has, of course, become a treasured piece of Harry Potter arcana."
A copy of a first edition of the novel in "exceptionally fine condition" will be auctioned on November 9.