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When is Line of Duty back on BBC One for season 6?

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

Line of Duty season 6 stars

Now we’re sucking diesel! Filming for Line of Duty season six has officially wrapped, and the BBC has confirmed that we’ll see AC-12 trio Superintendent Ted Hastings (Adrian Dunbar), DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) back in action early next year in 2021.


The cast returned to Belfast to finish filming earlier in 2020 – alongside DCI Joanne Davidson (Kelly Macdonald), who’s described as “the most enigmatic adversary AC-12 have ever faced”.

After the coronavirus pandemic hit in March, production on Line of Duty came to an abrupt halt until filming could recommence in September 2020. That means, of course, that the air date has inevitably been pushed back.

But fans of Line of Duty are interested in one thing, and one thing only: watching season six as soon as we can.

So when will the police corruption thriller hit our screens? Here’s what we know so far.

When will Line of Duty be back on TV?

Line of Duty will be back in early 2021. Following delays, the BBC has now confirmed that Line of Duty series six would land on our screens 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.

Has Line of Duty been delayed?

Yes – filming for Line of Duty season six finally wrapped in November 2020, after production (which began at the start of the year) was hit badly by the coronavirus pandemic.

Martin Compston took to Twitter to announce the news, writing, “Another one in the bag, hope you all enjoy it when it comes, AC12 over and out for now!”

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.”

Earlier, on 27th August, the showrunner had tweeted that he was on a flight to Belfast “to self-isolate before resuming filming of #LineOfDuty,” while Compston also shared a picture of a new Line of Duty script. Since then, photographic evidence has emerged of the cast on set (courtesy of Jed Mercurio).

In fact, they seem to be having quite a lot of time – especially when Adrian Dunbar’s not around. Mercurio shared behind-the-scenes Line of Duty photos of what Vicky McClure and Martin Compston get up to when the Gaffer’s away…

Who is the guest star for Line of Duty series 6?

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.”

Macdonald recently 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.

Here was our first glimpse of Kelly MacDonald in character, 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…?

In November, the BBC released a first-look at Kelly Macdonald’s new character DCI Joanne Davidson.

Kelly Macdonald
Kelly Macdonald as DCI Joanne Davidson

Who is in the Line of Duty cast?

The main AC-12 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 (Our Girl), Andi Osho (Kiri) and Prasanna Puwanarajah (Doctor Foster).

Perry Fitzpatrick will also be part of the cast, having previously appeared opposite 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 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.

Will coronavirus be included in Line of Duty?

Mercurio recently revealed that series six may also reflect the coronavirus pandemic, as the cast and crew were in the early stages of filming when they were forced to halt production.

“We’re still discussing it,” he told Radio Times magazine. “At that point we were shooting a representation of life as it was, there was no social distancing, no mask wearing. Clearly that’s not the world we’re currently in, but what no one knows is how long we are in this fight.”

And in August 2020, he told us during a live Q&A with RadioTimes.com: “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 Jed 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.”

As for coronavirus safety protocols, the BBC said: “Together with independent health and safety consultants, in full consultation with industry partners, and in accordance with all current government guidelines on Covid-19, the Line of Duty production team will adhere to comprehensive protocols to ensure that the new series is produced in a safe and responsible manner.”

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.

What will happen in Line of Duty season 6?

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.)

Compston also told us during the live Q&A that he’d been revisiting the scripts.

“Not to sound like we’re a band and I’m trying to sell our newest album, but I was just reading the scripts again and they’re so good that I feel like it’s our second chance, another chance to go back to it and really do it justice,” he said.

The actor added: “For this year, I think we’ve filmed [episodes] one and two, and as a cast, we’ve got [the scripts for] three and four, and Jed is writing five and six and we haven’t seen them, and there’s a bombshell at the end of four and I’m desperate to find out what happens!”

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 series six be Line of Duty’s last?

In short: we’re not sure.

In a lot longer: Although the BBC hasn’t yet commissioned a seventh series, Mercurio certainly appears open to the idea. Rather than outright saying the sixth run would be the show’s last, he told the audience at the BFI & Radio Times Festival that he will be discussing future episodes with the BBC after series five has broadcast.

“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,” he said.

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.

Meanwhile Jed Mercurio was recently asked if he thought a US version of Line of Duty would ever be considered – and replied that although there has been interest over the years, the US market prefers a “home-grown approach”.

What happened in Line of Duty series five?

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, or take a look at our new TV shows 2020 page to find out what’s airing this autumn and beyond. You can also buy the Line of Duty seasons 1-5 boxset now on Amazon.