Author Dan Brown, has appeared in a London courthouse for the start of a legal challenge by two historians who claim that the premise behind his best-selling novel The Da Vinci Code is based on a non-fiction book they wrote.
Richard Leigh and Michael Baigent, two of the three co-writers of The Holy Blood and the Holy Grail, are suing their own publisher Random House, also the British publisher of the The Da Vinci Code.
They allege Mr Brown lifted "the whole architecture" of the research that went into their 1982 non-fiction book, itself a bestseller.
The Da Vinci Code (referred to in court as DVC) suggests that Jesus married Mary Magdalene and fathered a child by her, a suggestion also put forward by The Holy Blood and the Holy Grail (referred to in court as HBHG).
“There can be no dispute that Brown was aware of the importance of the HBHG to the central theme when he wrote DVC,” Jonathan James, representing Mr Baigent and Mr Leigh, told the High Court.
"It was not only used as a source, it was an essential point of reference for the making of DVC," he said. Mr James argued that this was an infringement of his clients’ copyright in the United Kingdom.
But the lawyer representing Random House, John Baldwin, is expected to argue that the impact of such an injunction would actually damage the art of writing.
"The claimants contend that their idea is protected by copyright, whereas Random contend there is no copyright in information of this nature, and that in any event there was no copying," Mr Baldwin told the court.
The publisher of both books said for its part it regretted the legal action. “Random House takes no pleasure in defending a legal action that it believes is without merit and we are confident that we will prevail," Gail Rebuck, chief executive of the Random House Group said in a statement.
Henry Lincoln, the third co-author of The Holy Blood and the Holy Grail, has not entered into the legal action.
Movie adaptation
If Mr Baigent and Mr Leigh win an injunction, the case could bar Random House from publishing Mr Brown's book and affect the distribution of a major Hollywood adaptation which Sony Pictures plans to release in May.
Lawyers on both sides of the case have declined to comment on how the trial might affect future sales of The Da Vinci Code which has sold more than 36 million copies in print worldwide or how it may impact the British release of the heavily anticipated film adaptation of the story.
The book is a religious thriller that explores conspiracy theories of a Vatican cover-up of the true story of Jesus that are similar to themes in Mr Baigent's and Mr Leigh's book. Both books have drawn heavy criticism from the Roman Catholic Church.