Tributes are flowing for Game of Thrones actor Andrew Dunbar who died suddenly on Christmas Eve in Belfast.

According to The Sun, local media outlets are reporting Dunbar, aged in his 30s, was found dead at his home.

Dunbar played the body double for Theon Greyjoy and Belfast Live reports he had also appeared in hit BBC show Line of Duty.

Head of Crowd Makeup on Game of Thrones, Pamela Smyth, said Dunbar "stood out" from other extras on the set.

"Even among the thousands of extras that came through the crowd room on Thrones – Andrew always stood out.

"Always professional and mannerly with a big broad beaming smile. A beautiful soul – he will be missed by all the GoT family," said Smythe.

And close friend Graham Smith posted a touching tribute to Instagram.

Game of Thrones; Principle Stills Photographer, Helen Sloane, shared her memories of Dunbar's professionalism.

"Yesterday morning we heard the awful news that we lost one of our Thrones Family. Andrew Dunbar was an absolute gem. Funny, charming, beautiful – and that impression of Miguel will never be beaten.

"When we were setting up to shoot the season 8 campaign – a stand-in was required. Knowing exactly who I wanted – the hunt for Andy began.

"They told me he had just left and I ran out to the car park after him and asked if he would be up for it.

"He said he was heading out that night – but said he wanted to do anything to help. He came back in and got back into costume just for me."

According to The Sun it is not yet clear how Dunbar died.