THE cast of Line of Duty including Adrian Dunbar reunited ahead of series six - and it looks like one of them has teased a spoiler if fans of the show's theory are to be believed. 

Martin Compston, 35, delighted fans by sharing details of his catch-up with co-stars Vicky McClure and Adrian Dunbar on Instagram.

The actor, who plays Steve Arnott in the BBC hit, said "Cannae beat a catch up with these two. Next time we’ll most likely be in uniform or at least Adrian will I’ll be in a new 3 piece."

His co-star Vicky also shared a picture of the meeting. 

Some fans, however, spotted Adrian, who plays Ted Hasting, had an H on his jacket.

The mystery surrounding who criminal mastermind H has left fans of the show in tenterhooks - until perhaps now.

One joked: "Ooohhh it's H H." 

Another added: "Not only is he H but he's H H."

Despite fans getting excited by the actor's winter coat, the logo is also used by the outdoor clothing line Helly Hansen. 

You didn't think they would give it away that easily?