By Deirdre McKeever
The trailer for the highly anticipated sixth series of Line of Duty has finally been unveiled by the BBC.
The clip introduces guest star Kelly Macdonald (Boardwalk Empire, Trainspotting, No Country for Old Men) as Detective Chief Inspector Joanne Davidson, the senior investigating officer on an unsolved murder case.
The first episode of season six is set to air on BBC One Sunday, March 21 at 9pm.
Vicky McClure, Adrian Dunbar and Martin Compston are all set to return as anti-corruption officers Kate Fleming, Ted Hastings and Steve Arnott.
Shalom Brune-Franklin (Roadkill, Our Girl) will be making her debut on the show as DC Chloe Bishop, a new addition to the AC-12 team.
This will be the longest series of Line of Duty yet, comprising seven episodes which will air weekly.
The Season five 90 minute finale in May 2019 drew in 9.1 million viewers in the UK.