The tragic story of the little boy who played Michael Banks in Mary Poppins.

The film has been a part of millions of childhoods for decades.

But behind Mary Poppins, there’s a devastating story about its famous child stars.

Although Julie Andrews and Dick van Dyke were the leading stars of the 1964 musical, fans will always remember Karen Dotrice and Matthew Garber for playing the parts of little Jane and Michael Banks.

But what many fans don’t know is that Matthew Garber’s acting career ended abruptly – and tragically.

Starring in Mary Poppins at just eight years old, Matthew also starred in two other Disney films, The Three Lives of Thomasina and The Gnome-Mobile.

As he entered his teenage years, Matthew stepped away from acting for several years.

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But little did he know, he would never appear on film again.

On a holiday in 1976, Matthew unknowingly contacted hepatitis.

He was unaware that he had the disease, and by the time he returned home to London, the disease had spread to his pancreas, becoming untreatable.

Just a year later, the actor passed away at 21 years old.

At the time, speculation arose that Matthew had contracted the disease through drug use, however his brother Fergus denied the claims, adding that the hepatitis likely came from consuming “bad meat”.

Following Matthew’s death, Karen spoke about the loss of her on-screen brother.

"I can't imagine making movies would have been half as much fun without him," she said.

"He loved being naughty, finding and jumping off of small buildings on the back lot," she added.

"He did live a full life over his 21 years."

Karen's acting career dwindled away not long after she starred in Mary Poppins.

After a brief run as Desdemona in the 1981 Broadway production of Othello, Karen retired from show business all together.

Back in 2013, the former child actress admitted her regrets at ever taking on the role of Jane Banks.

"If I'd had my way, I'd still never had done any of those films, because kids should be kids," she said, according to The Telegraph.

"They should be learning and growing at their own pace – and learning things at the right time, rather than when it's convenient for others," she continued.

"The fact is that if you're living in a Justin Bieberesque type world surrounded by a bunch of yes people, the odds are you're going to struggle in later life. I've seen a lot of my peers go through terrible times and have to deal with all sorts of demons."

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