Line of Duty could return for a new instalment next year amid rumours the BBC are working on more work for AC-12.

And star of the show Adrian Dunbar, who plays Ted Hastings has teased that not all is as it seems after viewers were left disappointed by the identity of ‘H’ in the last series.

Fans of the show were left disappointed following a nine-year wait for answers, but Dunbar has said Buckells, played by Nigel Boyle, was not H.

Speaking to Radio Times, the actor said: "He’s not H. We just got the guy we could actually pin a charge on. We didn’t get H, we got Buckells, the patsy."

Dunbar revealed he thinks Chief Constable Philip Osborne was “probably” the man pulling the strings, "unless there’s another twist and someone’s pulling his strings".

Speaking of a new series next year, he added: "There’s been talk about a movie or a four-parter or two [episodes of] 90 minutes. We’d love to do it again. I’m really hoping something might happen next year.

"(Jed) has also devised a couple of templates as to how things could go”.

The final episode of the BBC One series saw Detective Superintendent Ian Buckells, played by Nigel Boyle, unmasked as the mysterious H, the corrupt police officer at the top of a criminal conspiracy.

In June, Compston prompted speculation among fans when he posted a photo of himself having dinner with McClure, Dunbar and Mercurio, captioning the image “Talking tattoo designs”.

The group previously agreed they would get “AC-12 million” tattoos in reference to the show’s anti-corruption police unit if they reached 12 million viewers.