Hong Kong filmmaker Lau Ho-leung was thrilled when he was invited to direct a movie based on real criminal cases that took place on the Chinese mainland in the 1980s.

As with leading directors from the United States such as Martin Scorsese and Quentin Tarantino, Lau finds villains fascinating.

Lau is following in the footsteps of a treasured tradition in Hong Kong cinema - the gangster film genre.

He is drawn to such films by the confrontation between good and evil, which often entails action, suspense and the unraveling of mysteries.

Lau has written film scripts for Hong Kong and Chinese mainland productions for more than 15 years.

He made his directorial debut with the 2015 film Two Thumbs Up, an action comedy about a gang of criminals who dress as policemen to commit a robbery.

The success of Two Thumbs Up caught the attention of Han Sanping, 65, a veteran film producer and former chairman of China Film Group Corp. At the end of 2017, Han offered Lau the chance to direct a true crime film based on criminal cases from the 1980s.

Han presented Lau with numerous criminal case histories. Lau immersed himself in them, read news reports from the time and viewed documentaries that could give him greater insight into the cases.

He chose the most dramatic elements of the cases, from which he formed a storyline.

Three months later, Lau submitted his outline for a cat-and-mouse chase, staged over the course of a decade, as a quick-witted police officer pursued a cunning gang leader in a city in southern China. The outline was quickly approved and Lau continued to work on the film, titled Caught in Time.

The movie, which stars US-born Hong Kong actor Daniel Wu Yin-cho and mainlander Wang Qianyuan will hit the big screen later this year.

Hong Kong filmmakers such as Lau have found a wealth of career opportunities on the mainland for more than a decade. With a huge market and big budgets, adept storytellers from the city have given full play to their skills, enabling them to continue the tradition of Hong Kong cinema.

At the 38th Hong Kong Film Awards last month, Project Gutenberg, a film coproduced by Shanghai Bona Culture & Media Co, Emperor Film Production Co and Shanghai Alibaba Pictures Co, was the big winner, sweeping seven awards including Best Film, Best Director and Best Screenplay.

Released in September, it has earned 1.27 billion yuan ($183,770), according to Chinese box-office tracker Maoyan.

The film, with 17 nominations, became the second most-nominated movie in the history of the awards. Only Bodyguards and Assassins, another Hong Kong-mainland coproduction, had more nominations, with 19 in 2009.

From 2016 to last year, 73 films were coproduced by Hong Kong and mainland filmmakers, contributing 18 percent of the Chinese box-office takings, according to entertainment research company Entgroup.

Among the 73, the action war movie Operation Red Sea, directed by Dante Lam Chiu-yin, earned 3.65 billion yuan last year, surpassing Stephen Chow Sing-chi's 2016 coproduction The Mermaid as the then highest grossing film in Chinese motion picture history.

These success stories demonstrate the quality of Hong Kong filmmakers' work. As the mainland has grown to become the second-largest film market globally, a group of Hong Kong filmmakers is writing a new chapter in the city's cinematic history by using the greater resources available on the mainland.