Last year, the 49-year-old was elected as an NPC deputy representing his home province of Shanxi, where he found the inspiration and shot his first films, including Xiao Wu, his award-winning student feature about a pickpocket.

Jia's latest enthralling feature, Ash Is Purest White, is also set in the coal city of Datong in Shanxi province.

The film grossed box-office takings of about 70 million yuan ($10.4 million), a record for his movies.

He owed the success of the film, he said, to an increasingly diversified film market and a phenomenal increase in the number of screens.

"I think a film market that is more sensible and diversified is taking shape, which is what we have been longing for," he said.

However, Jia also expressed worries that a small number of blockbusters dominated the box office last year.

He noted that the domestic box office exceeded 60 billion yuan in 2018, and about two dozen films took up more than half of that total.

"That was an indicator that a very small number of films are gaining the recognition from audiences," he said.