ROME — Art experts and conservative clerics are holding an unusual "trial" in Leonardo da Vinci's hometown aimed at sorting out fact from fiction in the "The Da Vinci Code" after many readers took the smash hit novel as gospel truth.

The event in Vinci, just outside of Florence, began Friday with an opening statement by Alessandro Vezzosi, director of a Leonardo museum. He said he will produce photographs and documents as evidence of the mistakes and historical inaccuracies contained in Dan Brown's best seller.

"Leonardo is misrepresented and belittled," Vezzosi said in a telephone interview hours before the event began. "His importance is misunderstood. He was a man full of fantasy, inventions and genius."

The novel's contentious allegations -- namely, that Jesus married Mary Magdalene and sired a bloodline -- have provoked unprecedented protest among Roman Catholic and Protestant conservatives, who claimed that Brown's characters inaccurately malign Christianity.

The book portrays Roman Catholic leaders as demonizing women for centuries and covering up the truth about the Holy Grail, which the novel says is Mary Magdalene herself.

Vezzosi said he will produce evidence through 120 photographs based on documents and paintings with the aim of "reassessing and disclaiming the author" of the mystical thriller, a mix of code-breaking, art history, secret societies, religion and lore.

Vezzosi said one example of the mistakes contained in the book is the statement that the Mona Lisa was made in Leonardo's image.

"There's a very big difference between Mona Lisa's and Leonardo's noses, mouths, eyes and expressions," he said, adding that he will compare two portraits to prove it.

Brown in the past has not said much about the controversy surrounding the blockbuster book, but he told NBC's "Today" in June 2003 that while the novel's main character, Robert Langdon, is fictional, "all of the art, architecture, secret rituals, secret societies, all of that is historical fact."

Organizers said there would be nobody speaking in the book's defense and the "verdict" would be contained within the presentations of the speakers.

But that does not mean the book will be completely hung out to dry: Hundreds of fans were expected to attend the trial.

"This initiative has received a lot of interest with people calling to confirm their attendance," Vezzosi said.

"The Da Vinci Code" has sold more than 7.5 million copies worldwide and is expected to be made into a movie. Its success has inspired guided tours in Paris that take fans to sites described in the novel, and it also has spawned a cottage industry in books seeking to debunk it.

More than 10 books have been written trying to discredit the historical and theological content of Brown's novel.

Monsignor Renato Bellini, vicar of Vinci, said the book reveals nothing about religion and contains a mystifying and inaccurate portrait of the conservative Roman Catholic movement Opus Dei.

"This book depicts the movement as a mysterious center of political and economic power that tries to hide the historical truth on Jesus and Magdalene, which is absurd," Bellini said.

A representative of Opus Dei is participating in the mock trial in an attempt to reassess the historical truth about the movement, Bellini said.