‘It was deliberately and monstrously broken’ - the heartbreaking story behind Helen Mirren’s wartime instrument on The Repair Shop at Christmas

Dame Helen Mirren is making an appearance on The Repair Shop at Christmas this year, and it's an unmissable episode.

Airing on Boxing Day on BBC One at 7.30pm, the festive special sees the legendary actress present the workshop crew with a wartime cello that has the most heartbreaking backstory - and they've got their work cut out to restore it to its former glory.

Helen explains that the cello belongs to Denville Hall, a London care home for performing arts professionals that she supports.

It was gifted to the home by the late theatre director Martin Landau, and Martin "had the most incredible story," as explained by Helen.

At the age of 14, Martin had been placed on "kinder transport" by his parents, to escape the Nazis, coming to England.

He'd been told he could only take one item with him, and he chose to take his cello. "Can you imagine this little kid on this train, with this little bag and this huge cello?" Helen asks.

She continues, "There's a movie in there I think, that image of a young boy and the moment of having to say goodbye to his parents, at that point not knowing he'd never see them again."

However, before he got on the train, a terrible fate was in store for Martin's beloved instrument.

"The Nazis broke the cello, cruelly," Helen reveals. She adds that it was broken "deliberately and monstrously." Despite the instrument then remaining unplayable, Martin held onto it for the rest of his life.

He left it, one of his most prized possessions despite what happened to it, to the residents of Denville Hall. "This beautiful instrument hasn't sung for 80 years, so we're hoping that this Christmas it will be heard again," Helen says, emotively.

Expert Becky Houghton is tasked with the restoration, and it's a very difficult job. "I feel so sad that it's been brutalised in this fashion," she says.

Becky continues, "The fact that Martin kept it all these years, it must've been so special to him, because who keeps a cello that's in two parts like this?"

However, the expert works her magic and the moment Helen sees the final result is a piece of festive magic.

A delighted Helen tells Becky the cello "carried the history of family, of love and dreams."

Congratulating Becky on her work, Helen calls the finished product "absolutely wondrous."

Gazing at the instrument and stating "I wish I could play," the icing on the cake is when The Repair Shop crew bring out renowned cellist Raphael Wallfisch to play for Helen.

He brings the actress's stint on the episode to a close with a beautiful rendition of Frank Sinatra's Have Yourself a Merry Little Christmas.

"How incredible to hear that," Helen concludes, as she rapturously applauds everyone involved in the restoration of an item with such significance.

Julia Donaldson and Rob Brydon will also feature in The Repair Shop at Christmas, which airs on Boxing Day on BBC One, at 7.30pm.