It’s the latest twist for the mega-selling conspiracy thriller “The Da Vinci Code”: a lawsuit against the book’s publisher for breach of copyright that could taint the novel and delay the much-anticipated movie version.

Michael Baigent and Richard Leigh, authors of the 1982 nonfiction book “The Holy Blood and the Holy Grail,” are suing publisher Random House, Inc. over the allegation that parts of their work formed the basis of Dan Brown’s novel, which has sold more than 40 million copies worldwide and remains high on best seller lists nearly three years after publication.