Martin Compston was interrogated by SNP MP Mhairi Black over clues for the Line of Duty final as the actor called on voters to turn out for the election.
The Paisley and Renfrewshire South MP spoke to the Scots actor about the upcoming ballot during an online rally - and couldn't help but quiz the star about the BBC crime show's season finale.
Taking on the persona of a true copper, the politician quizzed: "As you're here in a personal capacity, I'll remind you that you no longer reserve the right to be interviewed by someone one rank senior.
"At this moment in time, as you are well aware.,there is a great public interest surrounding a clandestine network of corrupt police officers working with organised crime.
"So let's not waste time here sir, are you the fourth man known as H?"
The Greenock-born actor, who stars as DI Steve Arnott in the hit BBC drama, refused to give any clues away ahead of Sunday night's episode as he said: "No comment".
"Will you survive tonight's episode?" Ms Black quizzed, to which she received the same reply.
Martin went on to warn Scots not to leave the outcome of the election to chance as he blasted the UK Tory government for not 'caring about Scotland'.
Urging voters to back Nicola Sturgeon, he said: "If we had a functioning Westminster government that really cared about every region of the UK, didn't drag parts of the UK out of Europe against its will.
"And the decision, the big decisions, whether it be Scotland's future relationship with Europe, whether it be nuclear weapons on the Clyde, are best taken by the people who live here.
Martin, who lives in the US with his American wife, continued: "We can't forever live in this perennial situation where it's just Tory government after Tory government at Westminster, who do not care about Scotland.
"They just leave us in these utterly miserable situations, which we feel utterly powerless to deal with.
"We have to be in control of our own destiny."
