Anna Maxwell Martin to return to Line of Duty as the formidable Carmichael

The BBC has revealed that Anna Maxwell Martin will reprise her role as Detective Chief Superintendent Patricia Carmichael for the remainder of the season, starting from episode five.

AC-3 investigator Carmichael last appeared in the explosive series five finale, when she was brought in to grill Ted Hastings about his suspicious behaviour, and she proved to be a particularly no-nonsense figure.

Despite proving a tough opponent for Ted, he was exonerated when it transpired that corrupt lawyer Gill Biggeloe was attempting to frame him – but we can't imagine the gaffer will be too chuffed to see Carmichael again regardless.

Her return to the series comes after the revelation in episode four that the Central Police Force's various anti-corruption units would be merged into one – with Ted set to be forced into early retirement.

It seems likely, then, that Carmichael could be in pole position to take over as the head of the new combined unit in the not so distant future.

Speaking about her return to the show, BAFTA winner Maxwell Martin understandably didn't give much away as to what her character would be up to.

“Pat’s back, I can’t remember what she’s doing there, nor would I be allowed to blab, but suffice to say she’s got some new clobber and she’s ready to bust some balls," she said.

Read more: Line of Duty episode 5 first-look images reveal Jo Davidson and Steve Arnott working together

Line of Duty continues on Sundays on BBC One. Check out the rest of our Drama coverage, or take a look at what else is on this week with our TV guide.