Best known for playing mafia boss John Thomas 'Tommy' Hunter in the TV crime drama, the Scottish star had also recently joined the cast of Outlander prequel, Blood Of My Blood.

His sister confirmed his death on X, writing: "It is with great sadness that we announce the passing of Brian James McCardie, beloved son, brother, uncle and dear friend to so many.

"Brian passed away suddenly at home on Sunday 28th April. A wonderful and passionate actor on stage and screen, Brian loved his work and touched many lives, and is gone much too soon.

"We love him and will miss him greatly; please remember Brian in your thoughts."

She said funeral arrangements would be announced in the days ahead.

No cause of death was given.

McCardie's agent, United Agents, paid tribute on social media, writing: "We are shocked and so deeply saddened by the tragic news of Brian McCardie's sudden death.

"He was an actor of such great talent who we were lucky to represent, and our thoughts are very much with his family and friends at this difficult time."

A statement from Line Of Duty producers Jed Mercurio and Simon Heath and the team behind the hit show, said: "We are deeply saddened to hear of Brian McCardie's death.

"We feel honoured to have worked with Brian on Line Of Duty. Brian was an incredibly talented actor, and the lasting impact he had as Tommy Hunter is testament to the power of his performance.

"Off screen, Brian couldn't have been more different from the character he played - he was warm, funny and charming. Our thoughts are with his loved ones at this difficult time."

With a career stretching over three decades, McCardie had appeared in numerous TV shows over the years - but it was his role in Line Of Duty for which he was best known.

Tommy Hunter, a criminal boss turned police informant, was one of the show's original characters, who met a violent end early on in series two.

But Hunter went on to be mentioned in both series three and series five, and was a key player in the nail-biting police corruption whodunnit.

McCardie, who grew up Carluke, near Glasgow, appeared in an episode of Outlander, playing Sir Marcus MacRannoch, before being cast as the chief of Clan Grant in the forthcoming Outlander prequel.

The show, which centres around the lives of Outlander character Jamie Fraser's parents, is currently filming in Scotland, according to Starz network.

In Rob Roy, McCardie starred as Alasdair MacGregor, the brother of the title character, who was played by Northern Ireland actor Liam Neeson.

His other film parts include the 2013 adaption of Irvine Welsh novel Filth, which starred James McAvoy, and 2003 period drama Mr Barrington.

McCardie also had roles in 2019 Netflix series The Last Czars, along with prison drama Time in 2021, opposite Sean Bean, and Irvine Welsh's TV series Crime in the same year.

He also appeared in Sky Atlantic's Domina, set in Ancient Rome, where he played Roman statesman Cicero.