Line of Duty's Martin Compston promises a huge "bombshell" twist in season 6

"For this year, I think we've filmed [episodes] one and two, and as a cast, we've got [the scripts for] three and four, and Jed is writing five and six and we haven't seen them, and there's a bombshell at the end of four and I'm desperate to find out what happens," he said.

"We're just the same as everybody else and as far as H goes, as soon as we find him we're out a job," he added.

Prior to Compston's comments during the Q&A, which also featured Adrian Dunbar, Lennie James, Jed Mercurio and Craig Parkinson, Vicky McClure mentioned how keeping plot twists under-wraps has become increasingly difficult each series.

"As the series has gone on, your lips get tighter," she said. "Back then [when the series began] it probably wasn't such a big thing, nobody really knew what was happening. You didn't want to spoil it for anybody but that sort of gets harder as the show's progressed because there are so many secrets."

"H – that letter gets said a lot and it's just hard because you don't want to spoil it for anybody," she added.

The identity of H has been the most contentious topic throughout the last eight years of Line of Duty, with the villainous figure and leader of bent coppers continuing to be AC-12's number one target.

Line of Duty's sixth series was four weeks into filming when the coronavirus pandemic forced production to stop back in March.

With more episodes to film, Mercurio has revealed that the series will have to be wrapped by Christmas in order to air in 2021.

RadioTimes.com's Q&A with the Line of Duty cast and writers is available to watch on our Facebook page. Line of Duty is available to stream on BBC iPlayer. If you’re looking for more to watch, check out our TV guide.