Legal experts are eagerly awaiting the outcome of a British lawsuit accusing the publisher of  "The Da Vinci Code" by American author Dan Brown of copyright violations.  

A trial underway in London's ornate Royal Courts of Justice could have a wide-ranging impact on how authors gather and compile their research without being accused of copyright infringement.

The British branch of the publisher Random House is being sued by two authors, who claim The Da Vinci Code novelist Dan Brown stole his ideas from their 1982 non-fiction book entitled Holy Blood, Holy Grail.

Dan Brown leaves The Royal Courts of Justice in London,  March 14, 2006

The reclusive Brown has testified that the claim by British authors Michael Baigent and Richard Leigh is "completely fanciful."

Both books deal with a theory that Jesus Christ survived his crucifixion, took Mary Magdalene as his wife, and that their descendants survive to this day.  Theologians consider the books' theses false and heretical.

Brown's The Da Vinci Code has sold more than 40 million copies in the past three years, and a film based on the book - starring Tom Hanks - is due for release on May 19.

Copyright lawyers are watching the London case with fascination.

Among them is Robin Fry, of the London law firm Beachcroft Wansbroughs.  He has told a group of London-based foreign correspondents that a victory for Baigent and Leigh could adversely affect writers and academics around the world.

"I think it will put the brakes on a lot of research," Fry said.  "I think a lot of people will be confused about how they can use other works, because the fact is we all stand on the shoulders of others.  It is very rare that one can say that any work you have done is completely original."

Michael Baigent, co-author of Holy Blood,  Holy Grail, center, arrives at Royal Courts of Justice in London,  Feb. 28, 2006

But Fry believes there is so much money involved that neither side will want to destroy what he calls "the Da Vinci Code marketplace" if the verdict goes in favor of Baigent and Leigh.

"Inevitably, there will be hasty negotiations, there will be credits agreed for the authors [Baigent and Leigh] and there will be agreement regarding payment of royalties to those authors, so it will be a painful, difficult process but one cannot conceive that the whole Da Vinci Code industry will be stopped in its tracks simply by reason of this court case," he said.

Fry also expects The Da Vinci Code film will be released on schedule, even if Baigent and Leigh win.  He says Baigent and Leigh would not risk a countersuit by the filmmakers for lost profits, in the event a verdict in the authors' favor is overturned on appeal.

Random House also stands to win financially no matter how the case turns out, because it is the publisher of both The Da Vinci Code and Holy Blood and Holy Grail.  The publisher says sales of both books have been spurred on by publicity about the lawsuit.