Line of Duty writer and creator Jed Mercurio has teased that the upcoming sixth season of the highly addictive police procedural will feature "secret guest stars".

The showrunner tweeted a picture of the TV show's main stars Vicky McClure, Martin Compston and Adrian Dunbar at a meeting, and said they were "nervously awaiting arrival of secret guest stars".

McClure also teased fans by posting a selfie with her co-stars on Instagram and writing: "Hiya!"

Mercurio, also behind the edge-of-your-seat thriller Bodyguard, said that the sixth run of Line of Duty is "in the planning stage" and may return sooner than fans initially hoped.

He recently told Radio Times: "I would hope it's sometime in 2020, next year. But that's not something that we're able to confirm."

Line of Duty airs on BBC One.

For more television news click here