Steven Jan Vander Ark has been written for seven years a guidebook to J. K. Rowling’s best-selling series of “Harry Potter.” But a federal judge disproved his work, saying it was too close to the books he admired. Judge Robert P. Patterson Jr. of Federal Court in Manhattan wrote that “Plaintiffs have shown that the lexicon copies a sufficient quantity of the Harry Potter series to support a finding of substantial similarity between the Lexicon and Rowling’s novels.”

The decision was taken after five months of a four-day trial and it was a success for Ms. Rowling and Warner Brothers Entertainment, the company that has published all her seven novels. The judge sued a Michigan publisher from producing the lexicon and awarded the plaintiffs $6.750 damages.

Vander Ark, 50, said that he wrote the book in response of the demand his fans made him on his Web site called Harry Potter Lexicon. The 50-year-old who strikingly resembles Harry Potter added that he hopes to reaches an agreement with Ms. Rowling so he could publish his book.

Still, Vander Ark is allowed to publish another of his books, called “In Search of Harry Potter,” which will be released next month. The book is a memoir of Harry Potter’s travels to locations similar like the ones described in Rowling’s books.

The author of the lexicon said that his book is “a travel memoir.” “It’s not in any way the kind of a thing which should raise any red flags.”

Vander Ark is now living as a writer and he used to be a librarian and teacher at Byron Center Christian School in Byron Center, Michigan.