Even though the title seems to be a total giveaway and the title figure, Frederic Bourdin, appears chattering away to the camera from the very beginning, this is a film you'd be advised to know as little as possible about before seeing.

This engrossing and disquieting documentary really does have a stranger than fiction tale to tell.

In the opening minutes, we learn about the case of 13-year-old Nicholas Barclay who disappeared from his home in San Antonio, Texas, in 1994, told to us by family members. Next we move to Linares, Spain, and a recreation of the mysterious discovery of an unidentified teenager on a rainy night and from there we move towards the point where these two stories inexplicably cross.

Humour

The publicity looks to place The Imposter in the domain of modern documentaries like Man on Wire but its mixture of filmed recreations and interviews struck me as being classic Errol Morris.

It has odd moments of humour and absurd lines that might have come from a Coen brothers' script.

Around the halfway point you may find yourself wondering exactly how much juice there is in this tale of deception but the second half pulls some harsh twists and you sit studying these forlorn faces wondering if they are stupid, deceitful or evil.

THE IMPOSTER (15)

Directed: Bart Layton

Starring: Frederic Bourdin, Carey Gibson, Beverley Dollarhide and Charlie Parker

Length: 91 mins

****