J. K. Rowling and the Hollywood studio behind the film adaptations of her Hogwarts adventures are taking legal action to stop the unauthorised publication of a Harry Potter encyclopaedia.

The bestselling author has been incensed to discover that RDR Books, an independent American publisher, is planning to make a profit from a “Harry Potter Lexicon”. Rowling is planning to write a similar book herself - and donate all the royalties to charity.

This summer, she revealed that she was likely to write at least one more book – an encyclopaedia of Harry Potter characters, the background stories she had already written but had to cut, such as Harry’s schoolfriend Dean Thomas.

The author who, as a penniless single mother living in Edinburgh in the early 1990s struggled to find a publisher for the first book, urged patience as “I’d really like a break”, having just finished the seventh and final book, Harry Potter And The Deathly Hallows.

Harry Potter and the Deathly Hallows

Readers know that this is the last episode and that resolution will come only with heavy losses

BACKGROUND

• Harry Potter and the Deathly Hallows

• Harry Potter and the Deathly Hallows

• Explosive finale for Potter

BACKGROUND

• Harry mania...and there may be more

• Harry ever after?

• Potter breaks previous sales record

• Wizard day for biggest book event

Related Internet Links

• Watch Screen Online - Harry Potter special

• Visit Times Online's Harry Potter topic page

• Order Harry Potter and the Deathly Hallows online

Related Links

• Magical day for gays as Dumbledore is outed

Rowling’s notes, it has been said, are almost as detailed as those made by J. R. R. Tolkein for his Middle-earth, the setting of The Hobbit and The Lord of the Rings trilogy.

Yesterday, in a joint statement, the author and the studio said that they had issued a claim in the federal court in the Southern District of New York against RDR Books: “In this claim they objected to its infringement of their intellectual property rights through the publication of its forthcoming book, Harry Potter Lexicon.”

The book is believed to have been written by someone who runs one of the many Potter “fansites”.

Ms Rowling added: “It’s common knowledge that I love genuine Harry Potter fansites, which is why I created my own award to recognise their creativity and ingenuity.

“It’s also old news that I hope one day to write the definitive Harry Potter encyclopedia, which will include all the material that never made it into the novels, and that I will give the royalties from this book to charity.

“I cannot, therefore, approve of ‘companion books’ or ‘encyclopaedias’ that seek to pre-empt my definitive Potter reference book for their authors’ own personal gain. The losers in such a situation would be the charities that I hope, eventually, to benefit.”

Warner Bros said: “In taking this action, we are seeking to protect our intellectual-property rights in the interests of fans and so that everyone can continue to enjoy Harry Potter books and films in the spirit in which they were created.

“In doing so, we are determined to protect J. K. Rowling’s right to produce her own companion book to the Harry Potter series she created, and to donate all proceeds to charity, as she did with her previous companion books.”

In 2001, Rowling wrote two slim companion Hogwarts schoolbooks. Quidditch Through the Ages and Fantastic Beasts and Where to Find Them raised more than £15 million for Comic Relief.

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• Superfreakonomics by Steven D Levitt and Stephen J Dubner
• The Times picks the 50 best paperbacks of 2009
• Vincent van Gogh’s letters show the soul of the artist