PHOTO: Martin Compston sends Line of Duty fans into frenzy over theory Dot Cottan returns from the dead

30 April 2019, 20:31 | Updated: 30 April 2019, 20:36

The Scottish actor, who plays Steve Arnott in the BBC drama has shared a post with Craig Parkinson, who played Dot Cottan aka The Caddy.

Martin Compston has led fans to speculate as to whether a former key character will make a return the final episode of Line of Duty.

The Scottish actor, who plays Steve Arnott in the hit AC-12 drama, shared a photo of himself on social media with former co-star Craig Parkinson, who played Dot Cottan or "The Caddy,"in the second and third series, leading fans to speculate if he'd be returning from the dead in season five, episode six.

See his photo of the pair, which he teasingly captioned: "Looking forward to ep 6👀".

View this post on Instagram

Looking forward to ep 6👀

A post shared by Martin Compston (@mrmartincompston) on Apr 29, 2019 at 4:45pm PDT

READ MORE: Where is Martin Compston from and where did he get his Line of Duty accent from?

Naturally, the post has led fans to discuss what might be in store for the final episode, with some fans taking it more seriously than others.

One Instagram user named transitorydreams wrote: "Is Dot alive & in witness protection & Ted has been using Dot’s intel to try to take down the OCG from the inside (able to do this due to Dot) ever since series 3, or are you just two mates on a night out? Let us make a flow-chart of evidence... I don’t know, but I do know you’re trying to make it so none of us sleep until next Sunday! 😂 What a 😈 you are!"

Another opted for one one of Ted Hastings favourite lines, exclaiming: "Jesus, Mary and Joseph".

And the responses on Twitter were just as animated, with one fan exclaiming: "Christ on a bike! Don't know how much more I can take," while another said: "told you the caddy would be back!!!"

However some fans thought they could be just shooting flash back scenes.

See some of their reactions below:

READ MORE: See the reactions to the Line of Duty season 5 debut

Watch the dubbing fail in last week's Line of Duty episode:

Meanwhile, a former undercover police officer sent tongues wagging when he turned the theory behind "H" in Line of Duty on its head.

Peter Bleksley was asked by Eamon Holmes on This Morning who he thinks 'H' could be, he completely turned the question on his head, and said: "Is it a person or is it a place?"

The star of Channel 4's Hunted added: "Cast your mind back to the flats where people were being held."One was flat B.

"Just putting it out there."

Watch This Morning's video above to see what they think below:

READ MORE: Martin Compston praises Gerry Cinnamon

Find out what happened when Line of Duty got a Friends crossover: