Line Of Duty star Martin Compston said the upcoming series is “incredible” and that “everything will come to a head”, adding: “This is the end.”

The Scottish actor, 42, has starred as Detective Sergeant Steve Arnott in the BBC drama for more than a decade, first appearing as a member of the anti-corruption squad for the fictional Central Police force in 2012.

Compston joins co-stars Vicky McClure and Adrian Dunbar as he reprises his role for the next instalment of Jed Mercurio’s hit crime thriller, which is due to air next year.

The actor, from Greenock, discussed the highly anticipated seventh series while appearing on ITV’s This Morning on Thursday and said: “The scripts are incredible.

“There’s some amazing returning cast.

“I think with all of us coming back we probably … not got complacent, but thought it’d be a bit of a victory lap.

“It was genuinely the hardest one we’ve had to shoot. It was a pretty brutal shoot.

“But I think that’s because what we’re trying to achieve is very ambitious – we’ve got bigger and longer and more interview scenes, and a ton of action.”

Compston added: “It’s not for me to say when the show will ever end – but I think this is the end of the story arc that’s been building since series one.

“Everything will come to a head in this one.”

“Well, this is the end. I think it’d be fair to say that this is the end,” Compston replied.

Shephard went on to ask whether this is because “something dramatic” happens in the final episodes of series seven and Compston said: “Oh yeah.

“There’s not much I can say without giving it away, but I think Jed really wanted to wrap up this one.”

Compston also said he is “excited” about the upcoming series, adding: “You don’t want to sound like a band trying to flog the next album going, ‘This is the best one we’ve ever did’.

“But I really do think it’s the strongest script we’ve ever had. If we do it justice, then we will be on to a winner.”

He added: “The word of mouth was the rise of the show.

“We’ve got incredibly loyal fans, and I think (Jed Mercurio) wanted to kind of give them everything they wanted in this one.”

The upcoming series of the show will follow the anti-corruption unit AC-12, after being disbanded and rebranded as the Inspectorate of Police Standards, as the team are assigned their most sensitive case so far.

The star-studded cast features a guest appearance from Scottish actor Robert Carlyle, who Compston praised as “the most kindest, loveliest, patient man”.

Mark Bonnar, Owen Teale, Perry Fitzpatrick and Christina Chong are among the cast members returning to the show for its new instalment.

New additions include Laura Aikman, Amy Leigh Hickman and Levi Brown – who will play detective constables in the new series – as well as Tom Weston-Jones, who is joining the cast as Detective Inspector Dominic Gough.

Further details are yet to be announced.