Dan Brown, the American author, did not copy large parts of an earlier book to produce his blockbuster novel, The Da Vinci Code, the Court of Appeal ruled today.

Michael Baigent and Richard Leigh, two of the three authors of The Holy Blood And The Holy Grail, who pursued Mr Brown’s publishers Random House through the High Court to the Court of Appeal, now face a total legal costs bill approaching £3 million.

High Court judge Mr Justice Peter Smith cleared Mr Brown of copyright infringement of ideas set out in The Holy Blood and The Holy Grail in April last year.

But Mr Baigent and Mr Leigh took the case to the Court of Appeal, claiming the theme of the book that made Brown the highest-paid author in history was taken from their 1982 work.

The defendant in the case is not Dan Brown, who was a witness at the High Court hearing, but Random House, publishers of both The Da Vinci Code and The Holy Blood And The Holy Grail.

Last year, Mr Justice Peter Smith ordered that Baigent and Leigh should pay 85 per cent of Random House costs, that were estimated at nearly £1.3 million. They also have to pay their own legal costs which would be on a similar scale.

In addition, Random House was today awarded the costs of the appeal, estimated at £300,000 for each side.

The Holy Blood And The Holy Grail deals with a theory that Jesus and Mary Magdalene married, had a child and the bloodline continues to this day, with a secret society protecting their heirs against wicked conspiracies enacted by the Church.

It is similar to the theme explored in Mr Brown’s novel that has earned the author hundreds of millions of pounds worldwide since its publication in 2003.

Mr Brown, who spent three days in the witness box during the original three-week trial, said the accusations were “completely fanciful” and The Holy Blood And The Holy Grail was just one of the works studied for his novel.

He did not attend the appeal hearing.

Sarah Ahmad, an intellectual property lawyer at Allen & Overy, said: "The decision comes as no great surprise. A victory for Baigent and Leigh would have introduced a new legal precedent with significant ramifications for the entertainment and publishing industry.

"Today's ruling reaffirms the fundamental principal that ideas cannot be protected by copyright. As they say in the music industry, where there is a hit, there is a writ."

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