Martin, who plays Steve Arnott in the BBC series, shared his “relief” after the sixth series concluded on Sunday night and addressed the fact that some viewers didn’t get the ending they had hoped for.
The actor also remained tight-lipped on whether Line Of Duty will return for a seventh series following the divisive conclusion, which was watched by a record-breaking 12.8 million viewers.
Martin wrote on Instagram: “Hey folks now the madness is slightly dying down, just want to thank everybody who reached out about last night and the series as a whole, we’ve truly been blown away by the reaction and love for the show we’re proud of it.
“Fully understand it wasn’t the ‘urgent exit’ type ending some anticipated but we appreciate you sticking with us.
“Felt many emotions from excitement and anxiety at the hype to relief that it’s over. Now I just feel immense pride our show that started on Wednesdays on BBC2 has just smashed every overnight drama record since they began.”
Martin then revealed that he would be joining his co-star Vicky McClure and showrunner Jed Mercurio in getting matching tattoos to commemorate the record ratings.
“Finally myself, Vicky, Adrian and Jed made an agreement in the inconceivable and ridiculous scenario we ever got twelve million viewers we would get ‘AC12million’ tattoos,” he wrote. “We’ll see who’s good to their word…”
It seems Vicky was already on-board with getting the inking, after she re-tweeted Martin’s message before adding: “We are so grateful to you all. So much so looks like I’ll have the ink to prove it!”
Creator Jed also offered his own thanks to fans but also kept mum on whether Line Of Duty will be returning for a seventh series.
“We’re honoured and flattered by the viewing figures for#LineofDuty6,” Jed tweeted.
“We knew attempting to explore the real nature of corruption in our society wouldn’t appeal to everyone, but we do sincerely thank you all for watching. It’s been our privilege to share your Sunday nights.”
Line Of Duty’s season 6 finale was a disappointment to some fans – with a rating of just five out of 10 on IMDb.
One of the most controversial aspects of the finale was the revelation that DSU Ian Buckells was the “fourth man” behind “H” all along. Many viewers were left frustrated that he was only caught because of his repeated mis-spelling of the word “definitely”.
And while the finale tied up many unresolved storylines, there were still some gaping plot holes and storylines left unanswered, leading many fans to believe that there will be a seventh series.
Charlotte Moore, BBC’s Chief Content Officer, said of a seventh season on Monday: “Addictive event television, Line Of Duty has kept the nation guessing for the last seven weeks, so it’s no surprise that last night’s jaw dropping finale set a ratings record…
“Jed Mercurio is a master of his craft, and I would like to congratulate him and the entire cast and crew for delivering such an incredible drama series…
“I’m looking forward to having a conversation with the team about where we go next and what the future of the series might be.”
All six series of Line Of Duty are now available to stream on the BBC iPlayer.