'Da Vinci Code' Legal Battle Begins

"The Da Vinci Code" drama opens Monday -- but not in theaters.

The best-selling novel and soon-to-be film is at the center of a court challenge in which two men claim author Dan Brown ripped off their ideas.

According to Agence France-Presse, Michael Baigent and Richard Leigh are suing their own publisher, Random House, claiming Brown's book draws heavily on their 1982 best seller, "Holy Blood, Holy Grail."

Brown's 2003 book has sold more than 30 million copies worldwide and earned him $78.5 million in one year, instantly making the writer one of the world's richest.

Baigent and Leigh's book tackles theories that Jesus and Mary Magdalene married, had a child, and the blood line continues to the present day -- with the Catholic Church aware of the discovery and trying to suppress it.

A third author, Henry Lincoln, is not part of the lawsuit.

Brown's book, which combines thriller, detective and conspiracy theory genres, explores similar themes about the Vatican covering up the true story of Jesus.

The novel has been translated into 44 languages and has drawn criticism from the Roman Catholic Church and historians.

If Baigent and Leigh are successful and obtain injunctions preventing the use of their material, it could threaten the British release of the film adaptation of "The Da Vinci Code."

The big-screen version, costing $100 million and starring two-time Oscar winner Tom Hanks, Sir Ian McKellen and Audrey Tatou and Jean Reno, is scheduled to open on May 19.

The English High Court case is expected to last up to two weeks, barring a settlement. It is also likely to clarify the extent to which an author can use other people's research under existing copyright laws.

Brown acknowledges the theories of "Holy Blood, Holy Grail" in his novel. The villain is called Sir Leigh Teabing, a name that bears a remarkable resemblance to Baigent's and Leigh's surnames.