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Line of Duty series 6 release date: Your guide to the next series of the crime drama

Jed Mercurio’s police correction drama is coming back to screens – with a new guest lead.

Line of Duty season 6 stars

Warning: Line of Duty spoilers


Good news, fellas: it’s almost time for Line of Duty to return. Series six of the BBC police drama is expected to begin in March 2021, and we could hardly be more excited.

Despite production being shut down last year by the arrival of coronavirus – and despite the challenges of filming in the middle of a pandemic – the team behind Line of Duty have managed to pull it off and get the whole season filmed and finished.

AC-12’s Superintendent Ted Hastings (Adrian Dunbar), DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) are all back in action, alongside the anti-corruption unit’s newest member DC Chloe Bishop (Shalom Brune-Franklin).

And they’ll be going up against DCI Joanne Davidson (Kelly Macdonald), who’s described as “the most enigmatic adversary AC-12 have ever faced”.

Here’s what we know so far about the air date, cast, and plot of Line of Duty series 6.

Line of Duty series 6 release date: When will it air?

The BBC has now confirmed that Line of Duty series six will air in early 2021, with the show returning to BBC One before the end of March 2021. However, an exact date is yet to be announced, so watch this space.

Line of Duty series 6 cast: Who will star in Line of Duty?

Line of Duty’s three lead actors, Adrian Dunbar (Supt Ted Hastings), Vicky McClure (DI Kate Fleming), and Martin Compston (DS Steve Arnott), are all set to return.

Joining them will be Shalom Brune-Franklin, who plays DC Chloe Bishop – the newest member of the AC-12 team. The actress has previously starred in Cursed, Our Girl, Bad Mothers, and Our Girl.

Another new cast member for series six is actress and comedian Andi Osho, playing a character called Gail Vella. You may recognise her from I May Destroy You, Curfew, or Kiri.

Prasanna Puwanarajah (of Defending the Guilty, Patrick Melrose, Doctor Foster, and World on Fire fame) is also joining the cast, as is Perry Fitzpatrick – who previously starred alongside Vicky McClure in Channel 4’s This Is England and I Am Nicola.

Line of Duty - series 6 new cast
Line of Duty – series 6 new cast
Don Arnold/WireImage/Michael Tullberg/David M. Benett/Getty Images

It’s also possible that Taj Atwal (PC Tatleen Sohota) and Aiysha Hart (Murder Squad cop DS Sam Railston) will make a comeback.

Polly Walker‘s character Gill Biggeloe has been given a new identity, which doesn’t entirely rule out a return in season six, but there would have to be some sturdy justification for bringing her back.

The guest lead for series six of Line of Duty will be Kelly Macdonald, who will play DCI Joanne Davidson, “the senior investigating officer of an unsolved murder, whose unconventional conduct raises suspicions at AC-12”.

Kelly Macdonald

Line of Duty writer and showrunner Jed Mercurio said: “We’re honoured that Kelly Macdonald will join Martin, Vicky and Adrian in series six of Line Of Duty. DCI Joanne Davidson will prove the most enigmatic adversary AC-12 have ever faced.”

In recent years Macdonald has starred in The Victim and Giri/Haji. She is also known for her roles in Trainspotting, Gosford Park, State Of Play, No Country For Old Men and Boardwalk Empire.

We got our first look at DCI Joanne Davidson, sitting across the table from AC-12 in the interview room before “battle commences” and an interrogation begins:

We’ve also seen behind-the-scenes images of Kelly MacDonald and Vicky McClure working together side by side, raising big questions about the events taking place in season six. Is DI Kate Fleming back undercover? Or is she working alongside DCI Joanne Davidson for some other reason…?

How many episodes are there in Line of Duty series 6?

Update: There will now be seven episodes! The show was originally commissioned for six hour-long episodes, but in February 2021 it was announced that Line of Duty was getting an extra episode.

A press release informed fans: “AC-12’s highest priority will always be capturing bent coppers. With that in mind, we have requested and been granted an extension of an extra episode for our next series, making it our longest yet.”

We also got this video, straight from the officers of AC-12 themselves:

Line of Duty series 6 plot: What will happen?

Not even an intense AC-12 interrogation could get the Line of Duty team to give away any spoilers, but we do know a few things!

Season six will feature “a brand new case for AC-12” as they investigate DCI Joanne Davidson (Kelly Macdonald).

Martin Compston previously teased a bombshell at the end of episode four – and he said episode five was “worth the wait”. Vicky McClure commented that she’d “been sitting on these incredible scripts for some time now,” while Adrian Dunbar would only say: “Even with the imposition of COVID restrictions I can’t hide my excitement at getting the team back together. So many people wondering… what happens next?”

(Yes, Mr Dunbar. We are.)

Casting around for further clues about season six, it also looks like it might be set in the dead of winter? Seeing as Vicky McClure’s DI Kate Fleming is pictured on set wearing a stripy polo neck and a thick suit jacket. Or does AC-12 just have very intense air conditioning? We can but speculate.

Speaking of which, Jed Mercurio teased on Twitter that he’d hidden a clue in a behind-the-scenes photo of Martin Compston – claiming that the “inmate” opposite Compston had been deliberately hidden in the photo, but that eagle eyed viewers might just about manage to see an out-of-focus image on the camera monitor.

He added: “Clue: it’s not Julia Montague” – a reference to the character played by Keeley Hawes in his other BBC drama Bodyguard. Hawes’ own Line of Duty character Lindsay Denton was (spoiler alert!) killed off in series three, but Mercurio certainly enjoys stirring up speculation…

Similarly, the showrunner teased us with a so-called Line of Duty “cryptic plot clue” from the set of season six, winding up fans with a shot of a building painted with the word “Arnott’s”. (Steve Arnott – get it?)

And Mercurio again shared some new images in September to tease an impressive stunt that we’re set to see during series six – posting a photo of a van tipped over onto its side and singing the praises of the stunt team involved.

He wrote: “Huge respect to our stunts team led by Donal O’Farrell featuring ace stunt drivers Steph Carey and Dave Anders. It’s easy for me to write ‘van rolls’ – they make it happen.”

He followed that up in October with some shots of the AC-12 trio filming on location in Belfast. And based on Steve Arnott’s uniform, fans have been wondering whether they’ve spotted an important detail: is Arnott no longer a Sergeant?

Will this be the final series of Line of Duty?

No firm news just yet – but series seven has yet to be commissioned.

“I think as long as there’s an appetite from our audience for the show, we’ll keep going,” Adrian Dunbar said during an appearance on the Graham Norton Radio Show in January. “Why would we stop? We’ve managed to keep the standard, Jed [Mercurio] rather, has managed to keep the standard so high for so long, and people love the show. I hope it does go on.”

He added: “But of course everything is finite, I see Peaky Blinders is coming off after six fabulous seasons. When it ends, it will end, and we’ll have all had the most wonderful time.”

Mercurio himself told RadioTimes.com in 2017: “Whether I would go beyond six would depend on how series five went… at the moment there is a great appetite among all of us involved in the programme to do more. What we don’t know is whether there will come a point where we kind of lose that enthusiasm to keep going back.”

He followed this up in 2019 at the BFI & Radio Times Festival by explaining that he’d have a conversation with the BBC after series five: “Once series five has finished airing we’ll have a conversation with the BBC, with a view to whether there’s a possibility to series seven being commissioned. But we definitely know we’ve got series six.” (So has that conversation now happened? If it has, Mercurio hasn’t shared the news with anyone.)

Judging from series five viewing figures, a recommission seems likely. Its opening episode drew in a peak audience of over 8 million viewers, with an average of 7.8 million watching the entire episode — that’s larger than the season four finale in 2017.

Line of Duty series 6 trailer: When can we watch it?

Not just yet! We wait with bated breath.

How did they film Line of Duty during COVID?

Line of Duty was one of the shows that had to suspend filming in March 2020, when the coronavirus pandemic hit. However, the production team managed to kickstart filming again in September, and Line of Duty season six wrapped filming in November 2020.

Martin Compston announced the news on Twitter, writing: “Delighted we’ve finally wrapped series six! Tip of the cap to the production team for putting the protocols in place to provide a safe working environment and to the phenomenal crew, having the discipline and determination to work within the new parameters and get us over the line.”

Filming for Line of Duty season six originally got underway in February 2020, and we had initially been expecting the drama to air in 2020. However, as the coronavirus pandemic escalated, producers made the decision to suspend filming four weeks in to the shoot. Lockdown was officially imposed days later.

Line of Duty series 6 filming pictures
World Productions

In May 2020, creator Jed Mercurio gave an update to fans on The Andrew Marr Show, stating that it was “in doubt” whether Line of Duty would resume filming this year or have to pick back up in 2021. But by June 2020, during an appearance on the A Stab in the Dark podcast, the showrunner was more hopeful.

Several UK broadcasters, including the BBC, announced in July that they would resume TV production with new COVID-19 safety guidance. A major government-backed insurance scheme has also been launched, removing another obstacle to production.

And in August 2020, RadioTimes.com was able to host a livestreamed Q&A with Vicky McClure (DI Kate Fleming), Adrian Dunbar (Superintendent Ted Hastings), Martin Compston (DS Steve Arnott), Lennie James (DCI Tony Gates), Craig Parkinson (DI Dot Cottan), executive producer Simon Heath and showrunner Jed Mercurio.

Heath told RadioTimes.com that production would restart “soon”, while Mercurio said: “We’d love to be on air next year, so we really have to make sure we complete our filming before Christmas.”

Then, on 1st September 2020, the BBC announced that filming had officially resumed.

Executive producer Simon Heath said in a statement: “It’s been almost six months since we stopped shooting, but following our implementation of all the industry Covid protocols, we’re delighted to be able to resume filming series six safely.”

Mercurio added: We know Line of Duty fans are desperate for series six and we hope we can get it on air as soon as possible. Thanks so much for your patience in these difficult times.”

On the question of whether the drama will incorporate the pandemic, Mercurio told RadioTimes.com during a live-streamed Q&A: “We’re still talking about it. There are some things that we can do, some very simple things that the audience won’t notice, like have as many scenes outdoors as possible, which allows social distancing of the crew, and it’s a safer environment for COVID. So we’re looking at things like that, which are kind of invisible changes.

“But we would obviously have to think very carefully about doing visible changes.”

Martin Compston also had concerns about continuity between footage shot pre-lockdown and post-lockdown, joking: “We’ll have to accommodate the stone of weight that I’ve put on!” – while Mercurio teased a fake plot detail for season six: “Martin has to go undercover and it’s part of his disguise, to be a stone heavier.”

And appearing on The One Show in August, Martin Compston said: “I think if there’s changes that are possible in terms of moving scenes which were indoors, outdoors, where possible – but we really wouldn’t want to compromise the scripts.”

How to watch Line of Duty online

Line of Duty is available to stream now on BBC iPlayer. Series 1-4 is also available to watch on Netflix (as of 30th June 2020).

If you would prefer to own every episode, you can pick up the first five seasons in one handy DVD box set through Amazon UK.

BBC One is re-airing Line of Duty’s first series, starting from Monday 3rd August at 9pm.

Line of Duty recap: What happened in series 5?

You can see a summary of each episode here or read a (spoiler-heavy) synopsis below…

  1. Line of Duty series 5: episode 1
  2. Line of Duty series 5: episode 2
  3. Line of Duty series 5: episode 3
  4. Line of Duty series 5: episode 4
  5. Line of Duty series 5: episode 5
  6. Line of Duty series 5: episode 6

The fifth run of Line of Duty centred on John Corbett (Stephen Graham), a rogue undercover officer who would go to any lengths to catch ‘H’, the corrupt copper at the heart of the Organised Crime Group (OCG).

As the series progressed, we learned that Corbett had links to AC-12 chief Ted Hastings. It transpired that Corbett’s mother, Anne-Marie, was a police informant who had a relationship – professional and perhaps more – with Hastings during The Troubles in Northern Ireland.

Thanks to lawyer Gill Biggeloe – who was secretly in league with the OCG – Corbett believed Hastings was responsible for Anne-Marie’s death at the hands of paramilitary forces. And, again due to Biggeloe, Corbett was determined to prove Hastings was a bent copper.

But his mission was cut short when the OCG discovered Corbett was a rat and slit his throat.

Line Of Duty S5 - Episode 1

How did the OCG find out Corbett’s true identity? By the end of the series, it still wasn’t clear. According to OCG member Lisa McQueen, Corbett’s cover was blown thanks to a tip-off from Lee Banks, an imprisoned henchman from the same gang.

And where did Banks get this information from? Although never proven, many suspected Ted Hastings was the source. As AC-3 leader DCS Carmichael (Anna Maxwell Martin) theorised, Hastings could have leaked this intel as revenge – earlier in the series Corbett had beaten Ted’s wife.

After a large amount of bribe money was discovered in Hastings’ shabby hotel room, Carmichael then arrested him for conspiring to murder Corbett. And, going further, she intended to prove Hastings was ‘H’. However, this investigation only revealed that Biggeloe was actually trying to frame Ted for everything.

But although Hastings returned to active duty at the end of the series, he’s sadly not completely off the hook just yet…

Series six has been confirmed as taking place 18 months on from the events of the previous series.

Who is H?

Not one person, but four. Turns out that AC-12 had misinterpreted the dying testimony of Dot ‘The Caddy’ Cottan: instead of one police Kingpin called ‘H’, there’s actually a quartet of high-ranking police staff working with the OCG.

Looking back at the testimony, Steve Arnott and Kate Fleming noticed that Craig Parkinson’s character was tapping out the Morse code for ‘H’ on his left hand. Combining this signal with Cottan blinking at the letter ‘H’, the AC-12 detectives deduced he wasn’t trying to reveal the identity of one bent copper, but make it clear there’s four in the service.

Dot's dying declaration

In other words, there are four corrupt officers – and they’re NOT necessarily called ‘H’.

How much does this revelation change Line of Duty? At this stage in the show, not a lot. After all, as Fleming outlines, AC-12 has already discovered three of the four ‘H’s (again, just to clarify, their name doesn’t have to start with ‘H’). And they are…

  • DI Matthew Dot Cottan – as known as ‘The Caddy’
  • Lawyer Gill Biggeloe
  • Chief Superintendent Derek Hilton

There’s still one out there, though. As before, AC-12 are on the hunt for one corrupt senior member of the service.

The bad news? It could be anyone – their name doesn’t have to start with ‘H’. The good news? The final ‘H’ maybe isn’t as powerful as was feared – they were just one of four, not a single criminal mastermind.

Where is Line of Duty filmed?

Line of Duty is filmed in Belfast, where the cast relocate during shooting. Series six saw Martin Compston, Vicky McClure and Adrian Dunbar return to the Northern Irish capital, but the cast and crew were released when filming was halted due to coronavirus.

They returned to Belfast to continue filming later in the year, and wrapped production in November 2020.


Line of Duty will return in early 2021. Check out what else is on with our TV Guide. You can also buy the Line of Duty boxsets on Amazon now on Amazon.