Filmed in the faux documentary style, popularised by The Blair Witch Project and Paranormal Activity, The Last Exorcism follows a fourth generation evangelical preacher as he attempts to expose exorcism as pure bunkum.

With a camera crew conveniently behind him to capture every bump in the night, the man of God instead comes face to face with pure evil and perhaps the one bona fide case of demonic possession in his career.

Director Daniel Stamm attempts to create the illusion of reality by allowing the cast to improvise around a loose narrative framework and many of the actors play characters with the same Christian names.

However, Huck Botko and Andrew Gurland’s underlying script increasingly strains credibility and the camera has a knack of pointing in the right direction to capture vital parts of the narrative, when there should be some events which bypass the lens entirely.

The Last Exorcism opens in Baton Rouge, Louisiana, where Reverend Cotton Marcus (Patrick Fabian) tends to his flock.

Pressed into service at an early age, Cotton followed in the dog collar of his father John (John Wright Jr), praising the Lord to his faithful believers, his wife Shanna (Shanna Forrestall) and son Justin (Justin Shaffer).

The holy man has slowly lost his faith and has decided to expose the smoke and mirrors he uses to conduct fake exorcisms.

So he travels to Ivanwood with director Iris (Iris Bahr) and her cameraman to meet farmer Louis Sweetzer (Louis Herthum), who believes that his daughter Nell (Ashley Bell) is possessed by the dark.

Cotton conducts the fake exorcism and both Louis and Nell believe the evil spirit has been purged from her body.

Soon after, events spiral out of control and Cotton is forced to return to the Sweetzer homestead with the camera crew to consider the possibility that Nell might be under the influence of a demon after all.

‘I’m not comfortable that we’re in a house with a girl who is drawing pictures of me with my head chopped off,’ says the cameraman, speaking for us all.

The Last Exorcism is well made and night time scenes are particularly effective, captured in the light fixed on top of the camera which swoops back and forth, looking for figures in the enveloping darkness.

Fabian is an engaging central protagonist and Bell has staring lifeless into the camera down to an art form by the end of the film.

If Stamm’s film is anchored to reality, it cuts itself free for the overblown resolution, which attempts to give credence to the disturbing images in Nell’s drawings.

Crucially, if this was a real documentary made on the Sweetzer estate then the final frames logically suggest the footage would never see the light of a brand new day.

• Release Date: Friday 3 September 2010
• Certificate: 15
• Runtime: 87mins