Martin Compston yesterday sent Line of Duty fans into a frenzy after posing in a balaclava.
Viewers of the show thought he was giving a clue to a twist in the show, which is on BBC1 tonight.
The Beeb released publicity shots ahead of this evening’s episode showing Compston and co-star Vicky McClure searching countryside which had been taped off by police.
But Greenock-born Compston also posted an image of himself on Instagram which had fans speculating that he could be the show’s mysterious balaclava man.
The actor added a caption referencing a 2009 film in which he played a kidnapper, stating: “Completely random throw back to The Disappearance of Alice Creed? LoD5 Ep3 BBC One 9pm.”
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His addition of the question mark – and flagging up tonight’s LoD broadcast time – had fans guessing.
One of his 55,000 Instagram followers, Chrissy Louise, said: “This better not be a weird hidden secret that he is Mr Balaclava man.
“But there’s something funny about this photo I can’t work out.”
Another fan asked simply: “Completely random?”
The first series of the multiple award-winning show aired in 2012. Its fifth started on March 31.
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Emily Louise pleaded: “Stop – I can’t deal with the stress that this show causes me.”
Compston found fame in Sweet Sixteen but has become best known for his portrayal of anti-corruption unit Det Sgt Steve Arnott in the crime drama.
