Catholic group Opus Dei has called for the film version of The Da Vinci Code novel to be given an adult rating.
Tom Hanks stars in the film of the best-selling book
The organisation says children should be protected from what it calls "insidious" lies about Catholicism.
Spokesman Marc Carroggio said: "Any adult can distinguish reality from fiction. But you cannot expect a child to make proper judgements."
The group has aroused controversy in the past, with critics calling it secretive and ultra-conservative.
The film, based on Dan Brown's best-seller, stars Tom Hanks and Audrey Tautou.
Its conspiracy theories and thriller style, in which two code-breakers try to track down the truth behind the Holy Grail, have caught the imaginations of millions.
Directed by Ron Howard, the film is due for release in May.
Mr Carroggio added: "Merely adding a disclaimer that says 'fiction' is not enough."
"Although the story is absurd and at times somewhat humorous, it produces a hateful image of the institution and it is well known that hateful images like this produce feelings of hatred in those who lack a critical sense."
But he said Opus Dei would make "no declaration of war" against the film, adding he did not believe the film would have a negative impact on the organisation - believing it would be a "sort of indirect publicity for us".
"No one is going to make threats or organise boycotts," he told Catholic news agency Zenit.