Harry Potter star reveals Alan Rickman's secret tradition on set of the hit movie

Sirius Black actor Gary Oldman has opened up about the 'extraordinary' tradition Alan Rickman had while filming the iconic Harry Potter movies.

The legendary actor played Severus Snape in the film franchise, and died aged 69 following a battle with pancreatic cancer.

But his legacy lives on as one of the kindest among his fellow co-stars, who have praised the star for his repeated acts of generosity that they will 'never forget'.

And speaking about the late actor at Toronto International Film Festival, Oldman, who played Potter's godfather, revealed the one of a kind tradition he created behind the scenes.

Oldman noted that Rickman would 'bring in kids every single day' to watch the Harry Potter films being made, and to explore the magical set.

"He would bring them in from a school, he’d bring them in from the hospital, he’d bring friends and their kids in every single day for lunchtimes and things," he recalled.

The iconic character had a pretty wholesome behind the scenes tradition. (Warner Bros.)

The star added: "He’d take kids around to tour the sets, and we’d meet them."

Oldman said he 'thought that was the most extraordinary thing, that he was in this world that he got to be in, come in every day, and that he knew how much it meant to these kids'. "So, he wanted to share it," he added.

Rickman played Snape in all eight Harry Potter movies between 2001 and 2011, as they concluded just five years before his death.

But Oldman isn't the only co-star to have opened up about Rickman in the years following his passing.

Oldman worked with Rickman on just four of the iconic films. (Warner Bros.)

Daniel Radcliffe, Potter himself, spoke about how 'intimidated' he was by the Snape actor when they first started working together on the films.

In an interview with Happy Sad Confused podcast, he admitted: "Even hearing that voice, you forget quite how low it was until it echoes through you.

"I was so intimidated by him for the first three movies. I was terrified by him and was like, 'This guy hates me'.

But the star added: "Somewhere along the lines, he saw that I really wanted to do this and work at it.

"He saw every piece of stage work I did when he was alive. He would take me out afterwards and we would talk about it.

"He was one of the first people to say like, 'You should look at voice coaching and investigate all this stuff'."

Radcliffe admitted that he was 'so lucky' to have heard hi say those words.