The BBC police drama’s interrogation sequences have become a bit of a staple over the course of its six series, with last week’s setting a new record, as it clocked in at over 29 minutes.
Speaking to Newsbeat in the lead-up to the much-awaited series six finale, Martin – who plays DI Steve Arnott – revealed the scenes need to be shot in one take, meaning that if there are any mistakes, the whole team has to go back to the beginning.
Martin went on to explain why these scenes are usually toughest on him than the rest of his cast mates.
“As the lowest ranking detective on screen, I’m the one who’s got to drive the scene and present all the information,” he said.
“So I’ve got to come up with all these random acronyms and legislations and telemetry. The dialogue is challenging.”
Martin added that he does get an occasional moment of relief when “Adrian [Dunbar, who plays Hastings] is on one of his big rants”, which means he gets a second to “take a wee look at my notes and do some mental gymnastics”.
Line Of Duty fans are waiting on a lot of answers in the upcoming finale, not least about the identity of the so-called “fourth man” and Arnott’s future with AC-12, as he continues to struggle with an addiction to prescription medication.
Fortunately, Martin has assured us that “big answers” are coming, telling the podcast Shrine Of Duty: “There are a lot of pay-offs coming this Sunday. There are a lot of big answers that are coming, and I think it’s deserved.”
Line Of Duty’s finale airs on Sunday night at 9pm on BBC One.