Viewers of Jackie Chan's latest action thriller, Railroad Tigers, have been surprised to discover the film includes a major role for his son, Jaycee Chan.
The younger Chan's role wasn't revealed before the Dec 23 premiere.
Jaycee Chan has kept a low profile in showbiz circles since he was arrested for drug possession on April 18, 2014, and sentenced to six months in jail last January.
The first indication he wanted to return to the entertainment industry came in mid-June, when he appeared on the reality TV programme The Running Show.
Jackie Chan says the cast selection was decided by the director, Ding Sheng, when asked about his son's role during the preview in Beijing on Dec 22.
"I found Jaycee really fit the character when I wrote the script," Ding says.
Ding previously worked with Chan on the movies Little Big Soldier and Police Story in 2013.
Jaycee Chan didn't attend the Beijing preview. Other stars, including Wang Kai and Huang Zitao, appeared at the event.