A Bradford academic who blew the lid off the secretive world of Freemasonry is being hailed as the inspiration behind one of the most successful novels of all time.

And now lecturer Dr Robert Lomas has been drawn into the court room battle over accusations of plagiarism in the international bestseller The Da Vinci code.

Like the fictional adventurer and hero of the novel Robert Langdon, Dr Lomas is an internationally-known expert on spiritual symbolism and myth.

But the athletic fictional tweed hero has been sexed up for the big screen, with Oscar-winner Tom Hanks taking up the role in the movie, which is set to be released in May.

A lecturer at the University of Bradford's Management Centre for the last 27 years, Dr Lomas was responsible for delving into the mysterious world of Freemasons and lifting the lid on Masonic rituals in his book, The Hiram Key, first published in 1996.

Dan Brown, author of The Da Vinci Code, admitted using the book as his primary research source during the three-week trial in which he was accused by two historians of plagiarising their work.

But Dr Lomas said he has no quarrel with Brown using his ideas and added that the novel's success had boosted sales of his own book.

He said: "Dan Brown admitted in his court testimony that he had used The Hiram Key. And it was quite obvious that he had taken information for the climax of The Da Vinci Code from a description in my book."

The academic, who celebrates his 59th birthday today, counts Dan Brown as an acquaintance with whom he often corresponds via e-mail.

The pair are both signed to the same publishers, Random House.

He said: "I emailed him to say I wished I had thought of the idea to write a story around these myths.

"I had no issue with him using my book and wrote to him offering to come forward as a witness in the case."

The Da Vinci Code takes the romantic myths surrounding the survival of Jesus and the Knights Templar, weaving them into a page turner.

Dr Lomas, who became a Freemason after being introduced to the society by his mother-in-law, said the stories had been handed down within the organisation for centuries. "People like stories and myths, they capture the imagination," he said.

The closely-watched literary court case featured the media-shy Brown in the witness box, a debate about the Merovingian monarchy, the Knights Templar and Jesus bloodline, and revelations about the writer and his wife Blythe.

With sales of more than 40 million copies, the book uses some of the same ideas as the books The Holy Blood and the Holy Grail by historians Michael Baigent and Richard Leigh.

Both books raise the possibility that Jesus had a child by Mary Magdalene, that she fled to France after the Crucifixion and that Christ's bloodline survives to this day.

The case ended on March 20, and a ruling is expected by early April.