Author J.K. Rowling listens to a question from the media during a news conference in this Tuesday, Aug. 1, 2006 file photo, in New York. [Agencies]

As the creator of the Harry Potter books sees it, her kindness to fans might come back to haunt her. In papers filed for a lawsuit in Manhattan, J.K. Rowling says she feels betrayed by a fan, Steven Vander Ark, for his role in trying to publish an unauthorized reference work, "Harry Potter Lexicon."

Ark is editor of a Web site containing a fan-created collection of essays and encyclopedic material on the Potter universe, including lists of spells and potions found in the books, a catalog of magical creatures and a who's who in the wizarding world.

Rowling said she was especially irked that the site's owner and the lexicon's would-be publisher, RDR Books, continued to insist that her acceptance of free, fan-based Web sites justified the efforts.

"I am deeply troubled by the portrayal of my efforts to protect and preserve the copyrights I have been granted in the Harry Potter books," she wrote in court papers filed Wednesday in a lawsuit she brought against the small Muskegon, Mich., publisher.

She said she intends to publish her own definitive Harry Potter encyclopedia.

"If RDR's position is accepted, it will undoubtedly have a significant, negative impact on the freedoms enjoyed by genuine fans on the Internet," she said. "Authors everywhere will be forced to protect their creations much more rigorously, which could mean denying well-meaning fans permission to pursue legitimate creative activities."

She added: "I find it devastating to contemplate the possibility of such a severe alteration of author-fan relations."

She brought the lawsuit last Halloween along with film company Warner Bros., which owns the intellectual property related to the Potter books and movies. The lexicon's publication, previously scheduled for last Nov. 28, has been blocked by the lawsuit.

A telephone message left with RDR Books on Thursday was not immediately returned.

RDR Books publisher Roger Rapoport has said the lexicon is a "critical reference work" and would not compete with any official encyclopedia written by Rowling.

On its Web site, RDR Books said it was "determined to publish this book for the benefit of Harry Potter fans everywhere."

It said it "believes Ms. Rowling, who has championed the `Lexicon' for years, will love reading the book just as much as she does the Web site on which it is based."

In the past, Rowling had singled out the Web site and its editor for praise.