J. K. Rowling came to the edge of tears in a New York court yesterday as she defended Harry Potter from what she called “wholesale theft”.

The famously shy author, who had never testified in court before, had to ask for a glass of water to regain her composure when asked to describe what her seven-book series meant to her. “I really don’t want to cry because I’m British. It means setting aside my children and everything,” she said.

“These characters meant so much to me, and continue to mean so much to me, over such a long period of time. It’s very difficult for someone who is not a writer to understand. The closest I can come is to say to someone, ‘How do you feel about your child?’.”

Rowling set aside her writing and flew across the Atlantic to fight the planned release of a 400-page Harry Potter Lexicon, an A-Z guide derived from a fan website. She said that the book would interfere with her plan to publish her own Harry Potter encyclopaedia and donate the proceeds to charity, as she has already done with her two smaller guides, Quidditch Through the Ages and Fantastic Beasts and Where to Find Them.

Rowling had withering words for Steve Vander Ark, the librarian who set up the www.hp-lexicon.com web-site as a hobby in 1999 and assembled the projected lexicon book after reading the Harry Potter series almost 50 times. Comparing almost identical passages of Mr Vander Ark’s Lexicon with her own work, she denounced his “constant pilfering” and “utter laziness”.

“I believe this book constitutes wholesale theft of 17 years of my hard work,” she said. “It adds little if anything by way of commentary; the quality of that commentary is derisory; and it debases what I worked so hard to create.

“What particularly galls me is the lack of quotation marks. If Mr Vander Ark had put quotation marks around everything he had lifted, most of the lexicon would be in quotation marks.”

At one point Rowling sparred with the publisher’s lawyer, David Hammer, who sometimes struggled with details of her books. “With respect, Mr Hammer, I don’t think you are showing great familiarity with my work,” she said.

Despite the phenomenal financial success of the Potter books, Dale Cendali, her lawyer, told the court: “This case is not about money.” The case turns on the legal doctrine of “fair use”. RDR Books, a small Michigan-based publisher, claims that the Harry Potter Lexicon is a reference guide permitted by law.

Because of fears that the suit could cramp publishers’ freedom, RDR Books is being represented pro bono by Anthony Falzone, of Stanford University Law School’s Fair Use Project.

The publisher’s lawyers say Rowling “appears to claim a monopoly on the right to publish literary reference guides and other non-academic research relating to her own fiction. This is a right no court has ever recognised . . . It would threaten not just reference guides but encyclopaedias, glossaries, indexes and other tools that provide useful information about copyrighted works.”

The publisher argues that the lexicon provides fresh insights into characters such as Luna Lovegood and Draco Malfoy, as well as pointing out the author’s occasional mistakes. The lexicon notes, for instance, that Rowling makes one character, Marcus Flint, spend eight years at Hogwarts, though the school only has seven years.

Roger Rapoport, the publisher, said he planned to publish 10,000 copies, predicting that Rowling’s own encyclopaedia would sell three million. But her lawyers call the lexicon a “rip-off” that lifts 2,034 of its 2,437 entries straight from her work. “These things have no existence except in my words, so he has taken my creation,” she said.

Rowling was asked if she had expected that Harry Potter would ever become the worldwide publishing phenomenon that it has. “There isn’t a word big enough,” she said. “Flabbergasted. Astonished.”

The court case will last until Thursday, but a verdict could take several weeks.

Spell cheques

- J. K. Rowling’s seven Harry Potter books have been translated into 65 languages and sold more than 325 million copies worldwide

- The Sunday Times Rich List 2007 estimated her wealth at more than £545 million, making her the thirteenth-richest woman in Britain

- Warner Bros, which is suing alongside Rowling, has made film versions of five of the seven books, bringing in more than £2 billion at the box office

- The sixth film, Harry Potter and the Half-Blood Prince, is expected to be released this year. The studio says it will split the final instalment, Harry Potter and the Deathly Hallows, above, into two films to be released in 2010 and 2011

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