Trainspotting actress Kelly Macdonald has been pictured with the Line of Duty team as preparations for series six get underway.
The crime show's producers have described her as playing AC-12's "most enigmatic adversary yet" but have remained tight-lipped about what this will mean.
The 43-year-old will play Detective Chief Inspector Joanne Davidson, the senior investigating officer of an unsolved murder, whose unconventional conduct raises suspicions at the anti-corruption unit.
The behind-the-scenes picture shows her smiling alongside leads Martin Compston, Vicky McClure and Adrian Dunbar as they prepare for a read-through of the next series.
Creator Jed Mercurio announced in November that Macdonald was joining the cast.
He said: "Everyone involved in #LineofDuty is thrilled Kelly Macdonald is joining us for Series 6, playing AC-12’s most enigmatic adversary yet."
Simon Heath, chief executive and creative director of Line Of Duty’s production company World Productions, said: "The Line Of Duty team have always been huge fans of her work, so we’re thrilled Kelly has agreed to join us this series to pit her wits against AC-12."
Although the BBC has not confirmed an airing date for the sixth season, there has been some speculation that the show may not come back until 2021 due to it typically airing on a two-year cycle.
But at the start of January, seemed to verify the shows return within the next 12 months.
The most recent episode of Line Of Duty, series five’s finale on BBC One back in May last year, was one of the most watched programmes of the year, with 13.7 million viewers.
