‘Line of Duty’ star Martin Compston on Season 6: 'Big questions get answered!'

Line of Duty - Martin Compston as Steve Arnott
Martin Compston is trying to crack the case as DS Steve Arnott in Line of Duty. (Image credit: C) World Productions - Photographer: Steffan Hill)

A shadow is hanging over AC-12 as Line of Duty Season 6 begins on Sunday March 21. The anti-corruption unit’s boss Superintendent Ted Hastings (Adrian Dunbar) was found guilty of discreditable conduct and given a final warning at the end of the last series, leaving DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) disillusioned.

Written once more by Jed Mercurio, the new series finds AC-12 soon being drawn into a new case when they investigate the suspicious actions of DCI Joanne Davidson (Kelly Macdonald) during a murder enquiry.

We caught up with Martin Compston to find out more…

Martin Compston on where we find Steve in 'Line of Duty' Season 6

“The repercussions of series five are hanging over everybody and their relationship is strained after everything they've been through. But Steve is also struggling personally with his back still [he was attacked in series four] and he has problems with painkillers. There is some dark stuff because he's got this image in his head that he’s like supercop, but he’s coming to a breaking point.” 

Martin Compston on how the new case compares to previous ones

“Series three was our favourite because it felt like a culmination of the first three series and it built to a climax, and it feels like we are back to that point where series four and five have been building to the sixth, and big questions get answered. The show is going back to the essence of what made it great. A lot of the drama takes place in back alleys and there are double crosses, big interview scenes and some big set pieces, which were great to do.” 

Martin Compston on how AC-12’s past and the hunt for the fourth member of corrupt group 'H' will return to haunt them

“The past always looms large. But there have also always been elements that echo real cases and there's one later on which is jaw-dropping and based on stuff that's happened. When Jed merges true events with the past history of these characters, it's TV gold.”

Martin Compston on working with Kelly Macdonald

Kelly Macdonald in Line of Duty

Kelly Macdonald comes under suspicion as DCI Joanne Davidson in Line of Duty. (Image credit: World Productions - Photographer: Steffan Hill)

“A huge part of the success of the show over the years has been these magnificent guest leads we've had. It's probably the most excited I've been having the great Kelly Macdonald with us. She’s a Scottish icon!” 

When can I watch 'Line of Duty' Season 6?

The new seven-part series of Line of Duty airs on Sunday March 21 on BBC1 at 9pm and will also air on BBC iPlayer, where you can also catch up with the previous five series.

Caren Clark

Caren has been a journalist specializing in TV for almost two decades and is a Senior Features Writer for TV Times, TV & Satellite Week and What’s On TV magazines and she also writes for What to Watch.


Over the years, she has spent many a day in a muddy field or an on-set catering bus chatting to numerous stars on location including the likes of Olivia Colman, David Tennant, Suranne Jones, Jamie Dornan, Dame Judi Dench and Sir Derek Jacobi as well as Hollywood actors such as Glenn Close and Kiefer Sutherland.


Caren will happily sit down and watch any kind of telly (well, maybe not sci-fi!), but she particularly loves period dramas like Call the Midwife, Downton Abbey and The Crown and she’s also a big fan of juicy crime thrillers from Line of Duty to Poirot.


In her spare time, Caren enjoys going to the cinema and theatre or curling up with a good book.