In case you haven't heard, truth is stranger than fiction.

Bart Layton’s chilling, suspense-laden documentary, which walks and talks like a neo-noir thriller but draws its power from cold hard fact, makes this case as compellingly as any doc ever has.

In the late ’90s, a damaged young French-Algerian man, desperate to be anybody other than himself, won a meal ticket from Spain to the USA by convincing authorities that he was Nicholas Barclay, a Texan teenager who had disappeared three years prior.

Frédéric Bourdin, now nicknamed ‘The Chameleon’, features heavily here as a distinctly unreliable narrator.

What’s more remarkable is that the Barclay family, represented in the doc by Nicholas’ sister and mother, bought into Bourdin’s deception for several months.

Laughable though it might sound – their blonde-haired, blue-eyed, all-American son showing up 5,000 miles away as a mixed-race, dark-eyed Frenchman – it’s painfully easy to understand their desperation to believe Bourdin, who comes off like a smug, unhinged vampire leeching on the family in their time of crisis.

But what’s already a disturbing scenario veers into full-blown Gothic dysfunction as we discover more about the Barclays, who are on one hand the emotionally shattered victims we expect them to be, and on the other hand almost as unsettling as Bourdin himself.

Perhaps inevitably with a true tale this strange at its core, some have questioned whether the film itself is really all that, or whether it’s simply a competent messenger riding on the coattails of an extraordinary story.

But this dismissal only works if you flatly ignore the wealth of shrewd stylistic choices Layton employs.

Certainly he knows when to let his talking heads do all the work, when a broken sentence from Nicholas Barclay’s traumatised sister, or a damning assessment from a psychiatrist is all that’s needed.

But in between these segments Layton is doing far more than filling the gaps.

He segues from truth (home-video footage, audio from police phone calls) to fiction (clips from ’70s cop shows, reconstructions of described events) with hypnotic and alarming ease.

His film’s final shot combines the two, packing a visually metaphorical punch that will bury its way into the darkest corners of your brain and refuse to budge for days.

And then there are the reenactments, subjective and skewed as they are, which serve as a beautifully photographed illustration of the power Bourdin wields as a storyteller.

He’s front and centre, a charismatic and seductive narrator drawing you in, encouraging you to sympathise, and it’s these straight-to-camera confessionals that make it hard to scoff at all the people Bourdin hoodwinked.

At times he’s clearly a sociopath, but at others you’ll catch yourself being disarmed by him, his undeniably sad roots and his twisted emotional logic: a child without a family latching onto a family without a child.

And gone but not forgotten is the innocent third party in this gruesome triangle – the missing Nicholas Barclay, whose absence speaks haunting volumes.

What Layton creates is a singularly uncomfortable experience: you’ll feel sympathy and rage and revulsion all at once; you’ll be both repulsed and drawn in by Bourdin, both suspicious of the Barclays and guilty for doubting these poor people who have suffered so much.

You’ll be certain one moment, and lost the next.

It’s frightening, vigorous and intoxicating cinema.

DVD Extras:

• Making Of
• Q&A