Jed Mercurio won't cast "posh" actors in his show 'Line of Duty' because he doesn't believe they can accurately portray working class characters.

Line of Duty cast

Line of Duty cast

The television writer is responsible for creating the hit BBC police drama, which stars Martin Compston, Vicky McClure and Adrian Dunbar, and he has admitted he overlooks thespians from privileged backgrounds because he wants performers who can accurately bring his gritty plots to life.

When asked if he looks to cast a certain type of actor in an interview with Pilot TV magazine, Jed said: "Not posh. So the regular cast we have come from working-class backgrounds.

"Martin and Vicky didn't go to drama school, they have a very naturalistic style of acting and are very credible as blue-collar working people, as is Adrian. We need actors who fit because the regulars define the kind of officers who are populating the world we have created."

The fifth series of the BBC show will be airing next month and Jed - who has also penned 'Bodyguard' and 'Bodies'- has spilled that the next season will focus on a new case for police anti-corruption unit AC-12 which is set around two years on from the previous run of episodes.

The squad will be looking "behind the mask" of a group of criminals named 'The Balaclava Men' controlled by a shadowy figure only known as 'H'.

Jed said: "We've never really identified them as proper characters. That was something we felt was long overdue."

Rochenda Sandall and Stephen Graham are part of the cast for the new series.