The actor returned to the BBC crime drama last week as her character was brought back in to take over anti-corruption team AC-12 after Superintendent Ted Hastings was told to take early retirement.
*Major spoilers ahead – you have been warned*
Following Sunday (25 April) night’s episode, a number of clues left viewers convinced that Carmichael is the mysterious “H” figure running the organised crime group.
One major clue included her unwillingness to discuss organised crime during Joanne Davidson’s interview, while eagle-eyed viewers noticed Carmichael tapping her pen four times during the interview.
They theorised that this was an Easter egg suggesting she is “H” in morse code, with morse code originally being used to name “H” by Dot Cottan as he died.
Appearing on This Morning on Monday (26 April), Maxwell Martin was questioned by presenters Phillip Schofield and Holly Willoughby about the pen tapping during the interrogation scene.
“That’s ‘H’ in morse code,” Schofield shouted, while the actor cracked up laughing in response.
“I think I was just bored, because those scenes are very long,” Maxwell Martin said. “I think I was just like, ‘what am I saying next?’”
A sceptical Schofield replied: “Yeah, yeah, yeah,” while Willoughby said: “You are such a brilliant actress that you really could just be pulling the wool over our eyes completely here and I think that might be what’s happening.”
Elsewhere in the interview, Maxwell Martin joked that Carmichael was just “misunderstood”, adding: “She probably just wants a nice cuddle, doesn’t she, Pat.”
Line of Duty series six concludes Sunday 2 May at 9pm on BBC One.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies