Murder in Paradise investigates the disturbing deaths of British backpackers in Thailand

And that's why the 2014 murders of backpackers Hannah Witheridge and David Miller seem all the more shocking in a place gorgeous enough for a Lonely Planet cover. Their brutally injured bodies were found on 15 September, with a bloodstained garden hoe nearby.

The police quickly arrested two men from the island's Burmese migrant community and charged them with rape and murder. If found guilty, they would be sent to death row.

Channel 4's Murder in Paradise looks into the circumstances of Hannah and David's deaths, the controversy surrounding the investigation and the cases of other backpackers who have died on the island. The hour-long documentary leaves you with the sense that there could be something deeply suspicious about these deaths - and the way they've been handled by the Thai police.

Because while there is no doubt that David and Hannah were murdered, there is doubt from human rights workers and certain DNA experts about who committed the crime. From the start, the investigation was plagued by allegations of corruption, ineptitude and violence.

18 days after two 22-year-old Burmese migrant workers, Zaw Lin and Wai Phyo, were arrested, they withdrew their confessions to the murders and alleged that they had been tortured into saying they'd done it.

The heritage of the men is important; the film contends that there is exploitation of the Burmese community on the island, who work predominantly in manual labour jobs with few rights. Were Zaw Lin and Wai Phyo simply scapegoats for the Thai mafia?

Following the conviction, a Thai police spokesman Dejnarong Suthicharnbancha defended its investigation into the murders, saying “I would like to reassure that the investigation process of police was transparent and of a standard that is acceptable.”

With rare footage of Zaw Lin and Wai Phyo in custody, plus undercover interviews with the duo in prison, the film uncovers a truly fascinating, desperately sad story. In the way that Making a Murderer leaves you unbelievably frustrated about the justice system, Murder in Paradise raises similar worries. Especially when it comes to sentencing someone to death.

What makes the case even more unnerving is that the island is no stranger to tourist deaths, with backpacker Luke Miller (no relation to David) found dead in a swimming pool only this year.

His family said they had concerns over the investigation, as did the family of Christina Annesley who was said to have died of natural causes. In 2015 a French tourist, Dimitri Povse, was found hanged outside his bungalow, with his death ruled as a suicide.

And in 2014, the same year as Hannah and David died, Nick Pearson's body was found by scuba divers in the sea after he disappeared following a night out with his family on New Year's Eve. In the film, Nick's family say they believed he was murdered.

“It's a beautiful place," says Nick's brother, "but that’s all a front for the deeper, darker things that are going on. And we’ve found out the hard way.”

Whether some of these deaths are, as the Thai mayor tells Channel 4, down to tourists living too fast and hard while on holiday, or whether there's something more sinister going on, the film can't possibly conclude. David Miller's brother Michael said after the conviction that "justice is what has been delivered" and that the Thai police had "conducted a methodical and thorough investigation".

Whatever the truth, Murder in Paradise offers a revealing insight into a tiny tropical island shrouded in mystery.

Murder in Paradise is on Wednesday 20th April at 10pm on Channel 4