A new addition to the lengthening list is a CD called 'Music Inspired by Da Vinci' . . . after all, you can't copyright the Renaissance master's name.

Dutch songwriter and producer Jan Kisjes said he composed the collection of 14 songs with religiously slanted titles like 'Fear of the Unknown' and 'Revelation o' the Truth' to get people to re-examine Christianity and their faith.

"I am a musical evangelist, " said Kisjes, 46, in his studio in the Dutch village of Dalfsen. "I think this book has opened the eyes of people."

The plot of The Da Vinci Code, which has sold more than 40 million copies worldwide, entertains the idea that Jesus and Mary Magdalene married and had a child, a theory that has prompted an outcry among Christian groups.

Vatican officials have called for a boycott of the novel and the forthcoming Hollywood adaptation starring Tom Hanks, on general release from 19 May.

'Da Vinci Inc', as the Da Vinci Code spinoff industry has come to be known, has thrived off the controversy. Like much of that merchandise, Kisjes' CD does not explicitly refer to the book or the movie, despite the film and the CD sharing the same corporate parent, Sony Corp.

Meanwhile, the head of Opus Dei says some good might come out of the work. Monsignor Javier Echevarria contended that Opus Dei came under attack because of the organisation's "attachment to the pope, our loyalty to the church, our rigour for the orthodoxy of faith". Opus Dei's website has seen a jump in hits, he said, and the group "has taken advantage of a good opportunity" from the negative image the book gives of it.