JK Rowling, said the case was not about money, but was about "an act of betrayal" by Steve Vander Ark who was supposed to be her fan.
The proposed book, The Harry Potter Lexicon, which JK Rowling claims copies her work, is based on an Internet fan site of the same name. JK Rowling says the book violates her intellectual property rights.
JK Rowling originally took legal action against Steve Vander Ark and RDR Books last year, and she stated she was "deeply troubled" by plans to turn the Harry Potter Lexicon website into a book.
The court case against Steve Vander Ark and his publisher RDR Books is expected to last most of the week.
