IT is the long-running police drama from the writer of Bodyguard which has kept viewers on the edge of their seats for years as the body count mounts and crime-count rises.

And now the Scots star of hit-BBC show Line of Duty has revealed he's terrified of seeing the character he plays bumped off in some grisly manner - and never knows if his doom is sealed until he reads the script.

Martin Compston is one of the founding members of the cast on the cop drama - which returns to screens later this month for a fifth series after a two-year absence - with his DS Steve Arnott forming the original line-up alongside Vicky McClure's DS Kate Fleming and Adrian Dunbar's and DCI Ted Hastings.

But the show makes no bones about killing characters off, with the anti-police corruption team they head up facing off with gangsters, serial killers and assorted homicidal threats.

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The cast faces more murderous challenges this season

Over the four seasons staple characters Tim Ifield (Jason Watkins), Danny Waldron (Daniel Mays), Georgia Trotman (Jessica Raine) and DS Matthew "Dot" Cottan (Craig Parkinson) have met their maker  - while ACC Derek Hilton (Paul Higgins) made it all the way to the end of series four before being killed off.

This time the plods are hot on the heels of the mysterious 'Balaclava men', a criminal gang linked linked to a conspiracy which may go all the way to the very top of the Metropolitan Police, and Greenock-born Compston says that the chance their characters may not make it to the final credits has become a running joke among the cast.

Speaking recently, he said that the scripts for series 5 are keenly read to find out if he's got a death scene in store.

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The actor said: I: “Vicky read it before me and she went, ‘Have you read episode three yet?’ I said I’d not read it, and she went, ‘Oooooh!’

“Sent me into a panic, and I texted Jed [Mercurio, the writer], and he went, ‘Don’t panic, you’ll be alright.’ And I went, ‘What the F is going on?'”

HeraldScotland:

The 'Balaclava men' are gunning for Compston

Compston's concerns may have been well placed, as he reveals he has already hit the mark when predicting a main character would be killed off.

He correctly predicted that either his own character or Dot would have to die by the end of series three, even though actor Craig Parkinson was convinced it would never happen.

“We already had series four commissioned, and I knew there had to be a pay-off, so I had a drink with Craig and I went, ‘Me or you’s going to get it. One of us is going to go by the end of the series,'” Compston recalled.

“And he was like, ‘No no, we’ve got four [series], both of us will make it.’ And I said, ‘No, one of us is going to get it.'”

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The actor later tweeted that fans of the show are in for an "immense" storyline, although details have been kept under wraps.

Line of Duty is a multi-award wining drama, including Royal Television Society Award and Broadcasting Press Guild Award for Best Drama Series, which has been upgraded to a prime time BBC1 slot after starting out on BBC 2.

While each series is a self-contained story, it has recently been revealed that a narrative strand runs through each outing which will become closer to being tied up in the the latest episodes.

Writer Jed Mercurio, whose other series Bodyguard also became a must-watch show, has said he always tries to achieve a decent gender balance in his work.

HeraldScotland:

A scene from series 5

The writer of the police procedural has revealed he prefers a 50/50 mix of men and women working on his projects.

Line of Duty has been praised both for its gritty realism and for the diversity of its cast - with women given choice parts and roles normally taken by men in other police dramas.

Mr Mercurio has said that he pushes to give his series a gender balance and wants to reflect the modern British police force, where women do the same jobs as men.

He said: “I do like to have gender balance, so always looking for ways to keep it as near to 50/50.

“And also because it’s a precinct drama I kind of like to reflect modern workplaces and so having come from a background of women doing exactly the same jobs as men, I think that’s very important as a message in TV.

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“I should also pay tribute to our casting team, what we do is we see a diverse range of actors for every role so in respect of Lisa McQueen, Rochenda’s (Sandall) part, we saw actors of all kinds of ethnicities and you just pick the best person for the job.

“Because there is so much talent out there, and so much diverse talent, it’s really important that people go up for roles that aren’t compartmentalised.

“I think we’re really proud of what we’ve achieved over the years.”

The writer  said he is unsure how long Line Of Duty can continue for, and will have to keep checking its longevity, adding: “I think a lot depends on how people respond to it.”

*The fifth season on Line of Duty will appear on BBC1 on Sunday 31 March.