Guides at one of London's most famous churches are being given fact sheets to help answer queries about its role in the controversial Da Vinci Code book.
Westminster Abbey features in the Da Vinci Code
Tourists have been quizzing Westminster Abbey staff since it appeared in the book about code-breakers trying to find the truth behind the Holy Grail.
The church says the book is theologically unsound and lists metal detectors among "factual errors".
Marshals and vergers are to be given sheets to address issues from the book.
The Da Vinci Code, by US author Dan Brown, has sold more than 20 million copies around the world, but since it was published another 10 books have been written to debunk it.
Its central claim is that the Holy Grail is really the bloodline descended from Jesus and Mary Magdalene - which the Church is supposed to have covered up, along with the female role in Christianity.
Brown has previously said: "All of the art, architecture, secret rituals, secret societies, all of that is historical fact."
But many historians and the Roman Catholic Church in Italy have dismissed his version of events.
Westminster Abbey has already refused to allow any filming on its premises for the movie adaptation.
The "factual errors" include metal detectors in the Abbey which do not exist and claims that Alexander Pope gave the eulogy at Isaac Newton's funeral.
In a statement, the Abbey said, it could not "commend or endorse the contentious and wayward religious and historic suggestions made in the book."
A spokeswoman added: "We get a lot of tourists, particularly Americans, asking about the book.
"It's just so guides can be able to have the facts in front of them."