As well as a move to BBC One, the hit drama will be welcoming a wave of new characters.
As hit police drama Line Of Duty debuts on BBC One on Sunday, here are the new faces joining the cast for the fourth series.
The Westworld star is back in the UK as she plays lead character DCI Roz Huntley, who finds herself at the centre of an anti-corruption probe when an abduction investigation begins to arouse suspicion. Known for her TV roles in ER, Rogue and The Slap, Thandie’s extensive film portfolio includes comedy Run Fatboy Run (2007) and The Pursuit of Happyness (2006).
Already a familiar face on screens, Jason takes on the role of forensic coordinator Tim Ifield. His most recent roles include Solomon Coop in Taboo with Tom Hardy and he played series regulars in Trollied, W1A and Love, Nina.
The star of last year’s The Finest will join the force as DC Jodie Taylor. Claudia played Jeanette Su in hit series Call The Midwife last year, as well as Shari in social media-themed Dixi.
Thandie will need a right-hand man as her character comes under fire, and Mark will be filling the position as DS Neil Twyler. The Vera star also appeared in cult teen series Skins (2012) and The Silence (2010).
Joining the story as Pc Farida Jatri, Anneika is more than familiar with the world of crime drama. She has already starred in Apple Tree Yard and Silent Witness this year and has previously had roles in Taggart and Above Suspicion.
Bringing another Huntley to the team, Lee will play DCI Huntley’s husband, Nick. Best known for playing John Bacchus in Inspector George Gently, Lee may be better known by younger viewers for voicing the famous protagonist Bob in the Bob The Builder series – a role he will reprise for the show’s movie, Mega Machines, this year.
Best known for playing Methadone Mick in last year’s Still Game, Scott will take on his new role as Michael Farmer.
Line Of Duty airs on BBC One at 9pm on Sunday.