Who is DCI Marcus Thurwell in 'Line of Duty'?

Marcus Thurwell Line of Duty
James Nesbitt as Marcus Thurwell in Line of Duty. (Image credit: BBC)

DCI Marcus Thurwell was first introduced to us in Line of Duty Season 6, Episode 5, and fans were stunned to see Bloodlands star James Nesbitt involved with the programme. Nesbitt even convinced fans he wasn't involved in the project, during an appearance on The Graham Norton Show, where he appeared to be angry that he was snubbed!

But now it's confirmed that he definitely is involved with the series, you might be wondering about his character's backstory, and why his character is important to the Season 6 storyline. Here's everything you need to know... contains spoilers!

Who is DCI Marcus Thurwell?

DCI Marcus Thurwell is a key character in Line of Duty, but we don't actually get to see who he is until Season 6. The first mention of him is in Season 3, where his name is seen on paperwork related to the investigation into child sex abuse at Sands View Boys Home. Thurwell was one of the officers on the case, but covered up information alongside CSU Patrick Fairbank.

We learn more about Thurwell in Season 6, Episode 5, where it's revealed he was the Senior Investigating Officer (SIO) at the time of Lawrence Christopher's death in police custody in 2003. This is also one of the cases that murdered journalist Gail Vella was investigating. It is revealed that Thurwell is corrupt, as the perpetrators in Christopher's death were able to change their appearance and get away with it, with the case discontinued by the Crown Prosecution Service (CPS).

Thurwell is linked to Chief Constable Philip Osborne, who was also present at the time of the Lawrence Christopher case alongside DC Ian Buckells.

AC-12 were able to link Thurwell to the Oliver Stephens-Lloyd case, a man who was murdered by the OCG before he was able to expose the truth about sexual abuse within Sands View Boys Home. At the time of this case, Thurwell served as a Detective Inspector under CSU Patrick Fairbank.

Superintendent Ted Hastings believes that Thurwell is linked to the OCG, and that he was instructed by Tommy Hunter to sabotage the investigation into Christopher's murder to protect his son Darren, who was one of the perpetrators. And could Thurwell even be H?

James Nesbitt

James Nesbitt is best known for his role in ITV's Cold Feet. (Image credit: Getty Images)

Who plays DCI Marcus Thurwell?

DCI Marcus Thurwell is played by James Nesbitt, who was actually involved in this series despite pretending he wasn't! Most recently, we've seen the actor in BBC's Bloodlands, which was also executive produced by Line of Duty creator Jed Mercurio. Other credits include Cold Feet, The Missing, and Murphy's Law.