Brand new Channel 4 show Murder Island starts on Tuesday, October 5 and is a hugely ambitious new format which blends factual, drama and competition, as four teams of amateur detectives arrive on an island, off the coast of Scotland by boat, and must compete to win a huge cash prize.

The teams have eight days to catch the killer, sifting through evidence, examining pathology and forensic reports and interviewing witnesses and suspects. They have to look beyond their own prejudices, learn new skills and gather evidence. Their investigations will be overseen by policing experts and actors will play the characters living on the fictional island of Hirsa.

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Failing teams will be taken off the investigation and leave the island. But if the last team can identify the killer and build a strong enough case to satisfy one of Scotland’s leading lawyers then they could earn a £50,000 reward.

The island

How many episodes of Murder Island are there?

There are six parts to this first series.

Are the people in it actors or members of the public?

We have both.

We have the eight members of the public who are amateur sleuths and competing for the prize. They are neighbours Chrissie and Caroline, Dot and Rox, who are best mates, brothers-in-law Andrew and Nick and couple Sarah and Richmond.

Then we have three real experts, Parm Sandhu, former Chief Superintendent at the Met, Simon Harding, retired Detective Chief Inspector, The Met Specialist Crime Unit (Homicide) and Graham 'Maca' McMillan, retired Detective Inspector, Serious and Organised Crime Unit, Bedfordshire Police.

Parm Sandhu with Graham McMillan and Simon Harding

And finally, there are nine 'characters' - Charly Hendricks, the victim, Hamish Gowdie, a no-nonsense Highlander, Jean Grant the postmistress, Tony Slade, pub landlord. Sonya Sisoulu is the island's teacher, Freddie Forrester a Glasgow gangster, Alicia Devere an agent, and Ishbel and Logan Corrie, both life-long islanders.

The characters, other than Charly, are all suspects.

Rox and Dot get to work

Do the experts know who the murderer is?

According to writer, Ian Rankin, who is known for his Rebus novels, they do not.

He said: "I can certainly say hand-on-heart that the real cops, the three retired detectives who are leading the teams, and chastising the teams for getting things wrong, didn’t know."

The viewers will follow the sleuths on their journey, too and be able to play amateur detectives from their settees.

What is Murder Island about?

Graham McMillan and Simon Harding

Eight members of the public will compete for a £50,000 reward after they take part in a murder mystery - on TV.

Written by Ian Rankin, one of Britain's most successful crime writers, the mystery starts as a body is been discovered on an island less than 20 miles off the west coast of Scotland.

The eight must try to unpick his plot and solve the crime.

They will be met on the island by senior investigating officer Parm Sandhu and her two deputies, Simon Harding and Graham McMillan (Maca) before being whisked off to the crime scene, the Manse, where the body of Charly Hendricks was discovered a few hours earlier.

The Manse is an old, rundown property that Charly had been renting from the local pub landlord Tony Slade. A murder investigation begins. Among the blood and forensics are the clues to understanding the victim and her lifestyle. Simon and Maca remind the sleuths of an old police saying: 'if you can discover how a victim lived it will help you to find out how they died.'

Is Hirsa a real island?

Hirsa is a fictional island community, but the island the team filmed on the Scottish island of Gigha. It's a community-owned island which is home to 163 people.

How do I watch Murder Island?

Murder Island is on 9.30pm Tuesdays, starting October 5 and is available on All4 after airing.

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