Chill winds and freezing weather can do nothing to stop the Line of Duty crew as Ted Hastings continues the hunt for bent coppers.
Most of the scenes on Sunday, February 23, were shot in Belfast city centre at the Public Library.
With stars Adrian Dunbar as the infamous Superintendent Ted Hastings, and Martin Compston as DS Steve Arnott, the pair were spotted in a scene set on the doorstep of the fictional police station at Pelbury House.
The BBC have already shared plot details about the sixth instalment of Jed Mercurio's hit thriller.
And they have revealed that this latest action carried on 18 months from the events of series five and the explosive plot features a new case for AC-12, focusing on a new Detective Chief Inspector.
As previously announced, Scottish actor Kelly MacDonald will star as DCI Joanne Davidson - a senior investigating officer on an unsolved murder case.
Writing about the first day of filming on Twitter, the show's creator Jed Mercurio said: "First day of filming #LineofDuty6 @BBCOne @worldprods. It's great to be back on the hunt for bent coppers. Rest assured our camera crew will do better than my amateur snaps."
The new series of Line Of Duty will premiere on BBC One later this year.
There is no firm date for broadcast yet but Adrian Dunbar said has hinted that the series will air in the autumn.
