Anna Maxwell Martin will return to Line Of Duty on Sunday, the BBC said.
The actress will reprise her role as Detective Chief Superintendent Patricia Carmichael, the corporation said.
Martin’s Carmichael appeared in series five of acclaimed drama Line Of Duty, when she was brought in as an independent investigator amid doubts over the integrity of Adrian Dunbar’s Ted Hastings.
Her return comes as Ted is facing a forced retirement, potentially opening the door for Carmichael to take control.
Martin said: “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.”
Martin, 43, is a two-time Bafta TV Award winner. Her previous roles include the BBC’s 2005 adaptation of Bleak House and the 2015 Agatha Christie adaptation And Then There Were None.
Line Of Duty returned for its sixth series last month.
Its first episode was the most watched episode of a drama since 2018.
Line Of Duty airs on Sunday nights at 9pm on BBC One and BBC iPlayer.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here