Jackie Chan discovered parents had craziest lives once he found out who they were

While Jackie Chan is one of the world’s most well-known movie stars, beloved for his roles in the likes of Rush Hour, Shanghai Noon and The Karate Kid, he didn't actually know much about himself – until relatively recently.

His father, whose first wife died in 1947, had two sons, while his mother, whose first husband also passed away in a Japanese bombing raid, had two daughters.

After Chan rose to fame, rumours began circulating that he was adopted and was going by a different name to the one he was born with.

The truth turned out to be far stranger than anyone could have imagined.

Chan’s mother, it transpired, had been a prolific gambler of Shanghai’s criminal underworld, while his dad was a Nationalist spy and gangland leader.

Director Mabel Cheung told the Guardian at the time of the film’s release: "The fact that his mother was an opium smuggler, a gambler and a big sister in the underworld was a big shock to Jackie and also to us.

"Everybody in Hong Kong knew that his mother was like a common housewife, very kind, very gentle."

In the film, which was commissioned by Chan, we find out that his parents first met when his father arrested his mother for smuggling opium.

Cheung, a close friend of Chan’s, recalled: “He got very angry. He said, 'If you know everything, why didn't you ask me? You can find out from somebody else.'

“Jackie had to intercede. He said, 'I invited these guys to come. You've got to talk more.'

“We had to befriend him, sing karaokes with him, dance a little bit, before he was willing to talk again. And of course he was reluctant to tell us about his wife as an opium smuggler."

While we see Fang - who died five years after the documentary premiered - returning to China for a reunion with his two sons, Shide and Shishen, the father said he didn’t want Chan to meet his two half-brothers.

Cheung also said Shide and Shishen’s neighbours had no idea they were related to a megastar, believing it would create huge upheaval.

When the film was released, Cheung said Chan had cried through watching rough cuts of the film, but hadn’t completed the finished product – suspecting it was too painful, especially given it featured some of the last footage of his mum, who died in 2001.

"He was visualising for the first time how it must have been for his parents to survive during the wars,” Cheung said.

“When you're listening to the story, you don't visualise that much, but when you see the actual footage, he actually got very emotional. Maybe that's one of the reasons why he doesn't want to see it again."