J.K. Rowling, the best-selling British author of Harry Potter fame, testified before a packed courtroom on Monday in a lawsuit to block publication of a Harry Potter lexicon. She told a judge that the book amounts to a "wholesale theft" of nearly 20 years of her hard work.

"It gives me no pleasure to take legal action, but I'm here today because I feel very strongly about an issue that affects many more people than just me."

Rowling sued U.S.-based RDR Books last year to stop publication of Steven Vander Ark's "Harry Potter Lexicon," claiming copyright infringement.

Vander Ark ran the popular Harry Potter Lexicon Web site, and RDR wanted to publish a print version of the site.
Rowling said the book is nothing more than a rearrangement of her own material and told the judge it copied so much of her work that it amounted to plagiarism.

"If books that plagiarise other works are permitted, authors, fans, and readers stand to lose. There are lots of books, in many languages, that comment on or criticise Harry Potter and I'm delighted about that, but the book in this case is different. It provides no analysis and virtually no commentary. It takes far too much and it gives far too little."

Outside the courthouse, representatives from RDR Books refused to talk about the case.

The trial comes eight months after Rowling published her seventh and final book in the series.

The books have been published in 64 languages, sold more than 400 million copies and produced a film franchise that has pulled in 4.5 billion US dollars at the worldwide box office.