It opens with a mutilated body, features a series of bloody murders and even portrays a monk flagellating himself with a rope.
But the most disturbing thing about the Hollywood adaptation of Dan Brown's The Da Vinci Code is its musical score and sound effects, according to the British Board of Film Classification (BBFC).
The producers of the new £40 million film, which stars Tom Hanks, Sir Ian McKellen and Audrey Tautou, were told that their request for a 12A certificate was inappropriate because the film's score was too tense for young children, and its sound levels accentuated the violence.
The BBFC told executives at Sony, who are distributing the film in Britain, that unless significant changes were made to the film's audio content they would end up with a restrictive 15 certificate, which would have had a serious impact on the film's box office prospects.
A move to turn down a film's certification on the basis of its soundtrack is virtually unheard of. Normally, film producers have to cut only visual scenes to get the certification they require.
The Da Vinci Code tells the story of a conspiracy to suppress the truth about Christ's marriage to Mary Magdalene and the fathering of a royal blood-line, and is littered with violent episodes. All of these have found their way from the book into the finished film.
The Sunday Telegraph understands that the board viewed two different rough cuts of the film at the beginning of last month.
David Cooke, the BBFC's director, saw a version that contained hardly any soundtrack and is believed not to have raised any concerns.
Difficulties ensued, however, when two of the board's examiners viewed a version complete with the full soundtrack the following week.
"It was when the movie was viewed again with the soundtrack that the problems emerged," a studio source said. "Everyone was full of praise for the score but the BBFC felt that the way it was being used to build up the tension was simply too much for very young children.
"The BBFC also thought that the film had a very high 'crunch factor'. You didn't just see the fight scenes, you heard the bones break."
The film's score is by Hans Zimmer, the 49-year-old German composer who has produced a string of film soundtracks, including Batman Begins and Gladiator.
Aware that anything other than a 12A certificate would have undermined the film's commercial prospects, Sony was forced to moderate the audio content for the finished version of the film. Last week, it was finally granted the desired 12A certificate by the board.
A BBFC spokesman said: "We advised Sony that, as things stood, the film would receive a 15 certificate unless changes were made. A good score is obviously there to build up the tension. But in this case, we felt it was making things too tense for a very young audience.
''The sound mix was also accentuating the violence to a degree which was unacceptable for a young audience."
The BBFC's decision to raise objections about the film's soundtrack provoked astonishment last night.
John Beyer, the director of Media Watch UK, the organisation that monitors television and films, questioned whether adjusting the sound was the right way to protect young people.
"You do have to wonder if just turning down the sound is going to help matters that much," he said. "Even after the sound has been adjusted, you are still left with the problem of the violent imagery and it's this kind of imagery which really worries people."
Sue Palmer, an expert on child development and the author of Toxic Childhood, said: "It is an interesting response by the BBFC. The soundtrack is another dimension which reinforces what we see without us being very aware of it. However, children will still be seeing scenes of violence that they cannot deal with.
"We seem to assume that children mature at a faster rate and can handle more explicit material, but they can't. They are as emotionally vulnerable as they ever were."
"...I believe.
