Line of Duty is a British police procedural and serial drama television programme created by Jed Mercurio and produced by World Productions for the British Broadcasting Corporation (BBC). It began broadcasting on BBC Two on 26 June 2012. The programme performed well and was quickly commissioned for additional series that aired in 2014 and 2016. After becoming the highest-rated series on BBC Two in 10 years, Line of Duty was promoted to BBC One, beginning with the fourth series in 2017, the fifth in 2019, and the sixth in 2021. A seventh series is currently in production and is scheduled to air in 2027.
The series stars Martin Compston, Vicky McClure, and Adrian Dunbar, among others. It revolves around Anti-Corruption Unit 12 (AC-12), a team inside a fictional police force tasked with "policing the police". Mercurio originally pitched the series to BBC One in 2011 but was turned down and directed towards BBC Two. After the two networks were restructured, the programme was transferred to BBC One.
Mercurio has written the entirety of the series, directed some episodes, and served as producer and executive producer. Filming of the first series took place in Birmingham, England, before moving to Belfast, Northern Ireland, for the remainder of the programme. Simon Heath, Stephen Wright, and Tommy Bulfin are additional executive producers of the show, which was also produced with Northern Ireland Screen and BBC Northern Ireland.
Line of Duty has secured an international cult following despite complications with international distribution rights. The series has been praised by many critics, although it was criticised by some for its conclusion of a long story arc at the end of series six. It set viewership records and became the highest-rated drama in the UK since 2002. The programme has received several accolades, including multiple nominations for British Academy Television Awards (BAFTA TV).
Synopsis Line of Duty follows DS Steve Arnott, a former counter-terrorism officer who is transferred to Anti-Corruption Unit 12 (AC-12) after refusing to agree to cover up an unlawful shooting by his own team. At AC-12 Arnott is partnered with DC Kate Fleming, a highly commended undercover officer with a keen investigative instinct. They work under the supervision of Superintendent Ted Hastings, uncovering corruption within the fictional Central Police. Throughout the series, AC-12 investigates seemingly disparate cases involving apparently corrupt police officers such as DCI Tony Gates (series one), DI Lindsay Denton (series two), Sergeant Danny Waldron (series three), DCI Roseanne Huntley (series four), undercover officer DS John Corbett (series five), and DCI Joanne Davidson (series six), among others.
AC-12 realises the pervasive nature of corruption and the police's deep-rooted links to an organised crime group. A long-running story arc revolves around discovering the identity of "H", a corrupt person or persons of senior rank within the police force who are instrumental in running organised crime.
Cast and characters Main + Name Portrayed by Series 1 2 3 4 5 6 7 Tony Gates Lennie James colspan="6" Steve Arnott Martin Compston colspan="7" Kate Fleming Vicky McClure colspan="7" Jackie Laverty Gina McKee colspan="6" Ted Hastings Adrian Dunbar colspan="6" Matthew "Dot" Cottan Craig Parkinson colspan="2" colspan="2" colspan="2" Jools Gates Kate Ashfield colspan="6" Derek Hilton Paul Higgins colspan="2" colspan="3" Nigel Morton Neil Morrissey colspan="3" colspan="4" Philip Osborne Owen Teale colspan="4" colspan="2" Tommy Hunter Brian McCardie colspan="2" colspan="5" Lindsay Denton Keeley Hawes colspan="2" colspan="4" Georgia Trotman Jessica Raine colspan="5" Mike Dryden Mark Bonnar colspan="4" Jo Dwyer Liz White colspan="5" Lester Hargreaves Tony Pitts colspan="2" Daniel Waldron Daniel Mays colspan="2" colspan="4" Gill Biggeloe Polly Walker colspan="2" colspan="2" Rod Kennedy Will Mellor colspan="2" colspan="4" Hari Bains Arsher Ali colspan="2" colspan="4" Jackie Brickford Leanne Best colspan="2" colspan="4" Terry Reynolds Shaun Parkes colspan="2" colspan="4" Sam Railston Aiysha Hart colspan="2" colspan="3" colspan="4" Joe Nash Jonas Armstrong colspan="2" colspan="4" Maneet Bindra Maya Sondhi colspan="2" colspan="3" colspan="2" Patrick Fairbank George Costigan colspan="2" colspan="2" Roz Huntley Thandie Newton colspan="3" colspan="3" Tim Ifield Jason Watkins colspan="3" colspan="3" Nick Huntley Lee Ingleby colspan="3" colspan="3" Jimmy Lakewell Patrick Baladi colspan="3" John Corbett Stephen Graham colspan="4" colspan="2" Patricia Carmichael Anna Maxwell Martin colspan="4" colspan="2" Lisa McQueen Rochenda Sandall colspan="4" colspan="2" Jane Cafferty Sian Reese-Williams colspan="4" colspan="2" Allison Powell Susan Vidler colspan="4" colspan="2" Rohan Sindwhani Ace Bhatti colspan="4" colspan="2" Andrea Wise Elizabeth Rider colspan="4" colspan="2" Roisin Hastings Andrea Irvine colspan="2" colspan="2" Tatleen Sohota Taj Atwal colspan="4" colspan="2" Joanne Davidson Kelly Macdonald colspan="5" Farida Jatri Anneika Rose colspan="3" Ian Buckells Nigel Boyle colspan="2" Chloë Bishop Shalom Brune-Franklin colspan="5" Chris Lomax Perry Fitzpatrick colspan="5" colspan="2" Nicky Rogerson Christina Chong colspan="3" colspan="2" Steph Corbett Amy De Bhrún colspan="4" Haran Nadaraja Prasanna Puwanarajah colspan="5" Ryan Pilkington Gregory Piper colspan="3" Gail Vella Andi Osho colspan="5" Medical counsellor Steve Oram colspan="5" Dominic Gough Tom Weston-Jones colspan="6" Shaun MassieRobert Carlyle colspan="6" Paula Beckman Laura Aikman colspan="6" Luke Tobin Levi Brown colspan="6" Nira Rashid Amy-Leigh Hickman colspan="6"
Recurring
Episodes
Production Development
Series creator and producer Jed Mercurio stated that he wanted to create something different from other programmes, and viewed the series as a "revisionist commentary on 21st-century policing". The series is produced by World Productions. Mercurio originally pitched it to BBC One, which turned him down, believing it to be too "problematic for a mainstream audience", and directed him toward BBC Two, which commissioned the series nine months later. Mercurio also served as the programme's showrunner. A second series was commissioned by the BBC on 25 July 2012. Mercurio became an executive producer from the second series onwards, alongside Simon Heath for World Productions and Stephen Wright for BBC Northern Ireland. Tommy Bulfin replaced Wright for the fifth and sixth series. A third and fourth series were commissioned in April 2014, followed by a fifth in May 2016. At the time of the fifth series renewal, it was announced that future editions of the programme, including the fourth, would move from BBC Two to BBC One. This decision came after the series's high viewing figures and a restructuring of the networks. Five days after broadcast transmission concluded on the fourth, Line of Duty was commissioned for a sixth series. In 2020, a special mini-episode was produced in support of Sport Relief. The special was promoted as a "deleted scene" from the fifth series and starred Compston, McClure, and Dunbar, along with Jason Isaacs and Lee Mack.
On 18 November 2025, the BBC confirmed a seventh series had been commissioned with Compston, McClure and Dunbar reprising their roles. Filming will commence in Belfast in Spring 2026.
Writing A long-running story arc is the unknown identity of "H", a suspected corrupt police officer believed to be the highest connection to the organised crime group. Despite not introducing this storyline until the end of the third series, Mercurio stated that he had crafted it from the beginning and purposefully gave multiple characters names beginning with "H" so he could remake portions of the story if needed. He added that this also allowed him to intentionally mislead viewers. Mercurio wrote many characters to be morally grey so that they would feel more relatable. He attributed this to his belief that the world is "more complicated" than good versus evil. Mercurio also frequently kills off key characters to keep the audience engaged. Some of the storylines have been loosely based on true stories. The opening scene of the programme featured the shooting death of a man mistaken to be a suicide bomber; this was credited to the 2005 police shooting of Jean Charles de Menezes, in which a man was incorrectly believed to be part of bombings in London. Additionally, the story surrounding the Sands View Boys' Home in the third series included references to the Jimmy Savile sexual abuse scandal. The BBC was initially uncomfortable at the mention of Savile and wished to exclude it but was persuaded by Mercurio to keep it. The series six murder of Gail Vella was based on the 2017 assassination of journalist Daphne Caruana Galizia. This series also featured an 18-month time jump from the conclusion of the fifth. Many of the colloquialisms that Hastings uses were inspired by Mercurio's Italian father and Dunbar's Irish dad. Mercurio opted not to incorporate COVID-19 into the programme as four episodes of the sixth series had already been filmed when lockdown, face mask, and social distancing guidelines, were introduced and it would have been too expensive to re-film.
Casting
Leading the main cast across all the series are Martin Compston and Vicky McClure, who portray Steve Arnott and Kate Fleming, respectively, two officers in AC-12. Adrian Dunbar also appeared in the first series in a supporting role as Ted Hastings and was promoted to the main cast beginning with the second series. Each series features an additional actor as part of the main cast who portrays a police officer who is being investigated by AC-12. These roles were performed by Lennie James in the first series, Keeley Hawes in the second series, Daniel Mays in the third series, Thandie Newton in the fourth series, Stephen Graham in the fifth series, and Kelly Macdonald in the sixth series. Craig Parkinson also held a supporting role in the first series and joined the main cast for the second and third. Parkinson originally auditioned for the role of Arnott but ultimately portrayed Matthew Cottan. Mercurio also decided to bring Hawes back for the third series as a result of her character's positive reception and made changes to the script. Mercurio killed off both Parkinson's and Hawes's characters at the conclusion of the third series. Despite this, Parkinson filmed new footage for flashback scenes in the fourth and fifth series. Jessica Raine and Jason Watkins each appeared briefly in the second and fourth series, respectively, and were both credited within the main cast. Anna Maxwell Martin was also featured as part of the starring cast in the fifth and sixth series but only appeared in the latter portion of each series. Line of Duty features a large supporting cast of recurring characters and guest stars.
Production design Peter Anderson designed Line of Dutys opening title sequence. From series two onwards, Maggie Donnelly worked as the costume designer. She gave Hawes lower-end outfits to reflect "how far [Denton] had sunk in her grief", but also included power suits to show where "she would have been in her career if fate hadn't dealt her that hand". Other outfits included pieces from brands including A.P.C., Marks & Spencer, and Tommy Hilfiger for McClure, Theory for Newton, and ME+EM for both Macdonald and McClure. Compston regularly wears three-piece suits, and his character became notable for the waistcoats. Compston attributed this idea to a friend's experience working in a call centre.