Ron Howard's film of The Da Vinci Code opens in the UK on 19 May

"It's not theology or history," he told the Los Angeles Times. "Spy thrillers don't start off with disclaimers."

His remarks have drawn criticism from Roman Catholic group Opus Dei.

"A disclaimer could have been a way to show [Sony Pictures] wants to be fair and respectful in its treatment of Christians," its US spokesman said.

Based on Dan Brown's novel, The Da Vinci Code claims Jesus married Mary Magdalene and had children, which was covered up by the Catholic Church.

'Conspiracy theories'

Last month, Opus Dei called on producers to begin the film with an announcement stating "any similarity with reality is purely coincidental".

But Howard said it was clear the film was "a work of fiction that presents a set of characters that are affected by these conspiracy theories and ideas".

"Those characters in this work of fiction act and react on that premise," he told the newspaper.

Earlier this week, a leading cardinal urged Christians to take legal action against both Brown's book and Howard's film.

"Christians must not just sit back and say it is enough for us to forgive and to forget," Cardinal Francis Arinze said.