Riding along with 'Da Vinci': new nonfiction books address the religious controversy surrounding Dan Brown's bestseller.(book The Da Vinci Code)

As sales of The Da Vinci Code continue to top 100,000 copies a week, according to Nielsen BookScan, a growing list of new and repackaged nonfiction books are playing off or piggybacking on the Double-day bestseller by Dan Brown. These aren't just existing titles, like Holy Blood, Holy Grail by Richard Leigh et al. or The Gospel of Mary Magdalene by Jean-Yves Leloup, which have become bestsellers in their own right following a one-hour ABC News special in November that explored the novel's controversial theories. The list also encompasses several new hardcover releases that appeal directly to Da Vinci Code readers, and which publishers have had time to sign up and publish as Brown's bestseller maintains its improbably long blaze.

"There's something going on here that's lot easily categorizable," said Client Distribution Services' Gilbert Perlman. "You rarely see …