Stranger Thing star David Harbour cried at the script for his new movie

David Harbour "teared up" at the script for his new Christmas movie.

The 47-year-old actor - who is known for playing the role of Jim Hopper in the Netflix hit series 'Stranger Things - is now starring in festive action-comedy 'Violent Night' as Santa Claus and explained that even though the movie was "really hard to get right", it turned out to be "very special" in the end.

He said: "I thought that was really special, really unique. And when I read it in the script, it made me tear up at the end and I thought, "Wow, that's special." Because, a lot of scripts, it's hard enough to get through them. This one I got through, and at the end in those scenes with him and her where he's saying, "I better get going now," it made me tear up and I was like, 'Oh, this could be really special if we get it right.' But I still, at that time, thought it was a big swing, and it was going to be real hard. We had to go to work real hard on it, and we did. But that was what made me want to do it, that it was so unique, and even though it was a big action movie, I got emotional at the end."

The film - which sees mercenaries take a wealthy family hostage in their home but encounter resistance when St Nick arrives - required the 'Black Sidow' star to learn to wrestle for its action scenes and he went on to explain that the training took "three or four hours" at a time.

He told Collider: " We had a month of training in Winnipeg, and then we went home for Christmas, and then we came back in January, [and] had another month of prep to train. But for that month in December, I was already eating because I wanted him to be big, so I was eating a lot and I showed up at these training rehearsals with these guys. We were doing wrestling, mainly jui-jitsu and wrestling, and I don't know if you've ever wrestled, I never had.

"You do this thing called pummeling in wrestling. Basically just grabbing a guy, and he grabs you, and you just do this for hours. And it is the most tiring and exhausting thing I have ever.... I've never been that tired in my life. We trained for about three or four hours a day, and then I would just go pass out and sleep like 16 hours and wake up in the morning and do it again. It was so exhausting. And these guys are so skilled, and they also make you look so good because they're doing the reactions. So you're just trying to keep up with their choreography. But they also were so sweet, they had endless energy and I was just exhausted.

But being able, at this age, to be paid to learn new disciplines and learn new things in life is such a gift."

'Violent Night' is in cinemas now.