The Bafta-winning actor, known for Cracker and The Full Monty, will play a police officer in the news series.
The drama featured a fictional East Midlands Constabulary - now a similar force could become reality.
The actor is ready to reunite the Line of Duty trio.
Gregory Piper from Halesowen says he loved his time on the show and cannot wait for its return.
Jesus, Mary and Joseph and the wee donkey! Ted, Kate and Steve confirm a seventh series of the hit police drama.
Adrian Dunbar, Vicky McClure and Martin Compston will all reprise their roles in the hugely popular drama.
McCardie recently starred in BBC drama Time, and was to appear in Outlander prequel Blood of My Blood.
Vicky McClure and Jonny Owen reveal their wedding on his daughter's BBC Wales radio show.
The Leicestershire-based performer was nominated for three Baftas earlier this year.
