Martin Freeman is leaving the movie world behind him for a bit to return to the UK for a new role in a six-part drama based on the true story of the disappearance of 22-year-old Sian O'Callaghan in March 2011.

Called 'A Confession', the new series is written by the Jeff Pope, the acclaimed screenwriter behind ITV's 2017 drama 'Little Boy Blue'.

The 'Sherlock' star will play Detective Superintendent Steve Fulcher who leads the team attempting to find Sian, eventually interviewing the chief suspect, local taxi driver Christopher Halliwell (Joe Absolom). Imelda Staunton also stars as Karen Edwards, the mother of Becky Godden, a 20-year-old who disappeared 10 years ago in 2003.

ITV's head of drama, Polly Hill, said: "It is wonderful to be working with Jeff Pope again on this compelling and important true story. I'm delighted that the brilliant Martin Freeman and Imelda Staunton are leading the cast, making this an unmissable drama for next year."

"I found this is a fascinating story to tell on a number of levels," added Pope. "On one hand it is a brilliant piece of detective work, but in order to find both girls Fulcher felt he had to deny Halliwell his rights as a suspect.

"It brings into question how we want our police to behave when someone goes missing. Should Fulcher have been praised as a courageous officer fighting for the life of a girl, or lose his career for riding rough shod over the law?"

It will likely be 2019 when we get to see 'A Confession', and given that it's ITV, Irish viewers will probably see it aired on one of Virgin Media's channels here.