As of June, China had listed more than 3 million people on a roll of drug users, up from 1.8 million in 2011, according to Liang Ran, a drug-control official in the Ministry of Justice. Chinese director Zhang Yimou in 2012. Credit:AP Millions more fly below the radar of police, and China's National Narcotics Control Commission estimates the number of drug users to be more than 14 million, roughly 1 percent of the population. In 2014, authorities seized 69 tons of illicit drugs, arrested nearly 890,000 people on possession-type charges and almost 170,000 more on charges related to production and trafficking. Among the celebrities who have been arrested on drug charges in the past 18 months are Jackie Chan's son, Jaycee, and his actor friend Kai Ko; the pop singer Yin Xiangjie; and actor Wang Xuebing, who had a major role in Black Coal, Thin Ice, which took top honours at the 2014 Berlin Film Festival. Yin and Chan spent months in jail; Ko delivered a tearful public apology but nevertheless found himself cut out of films including Monster Hunt, a partially animated family film that after hurried reshoots became the top-grossing Chinese movie of all time. Wang's drama, A Fool, abruptly had its May release date scrapped and arrived in theatres only in November with some of the supporting actor's scenes trimmed.

But in a one-party system where even today's Communist Party leaders maintain that art should "serve the state", authorities are not merely setting out to punish stars who break the law. They also seek, in a time of rapidly loosening social mores, to turn entertainers into moral models - and even model informants. A still from Zhang Yimou's film Hero. The campaign has caught even the most respected celebrities flat-footed. Last month, after Yin was arrested, the state-run New China News Agency interviewed director Zhang Yimou and about a dozen major stars about their attitudes on celebrity drug use. "I have seen many actors using marijuana together during their breaks ... It's terrible that artists are involved in pornography, gambling and drugs," said Zhang, who has directed such films as Hero and Raise the Red Lantern, and is in production on the big-budget The Great Wall starring Matt Damon. "This trend is unhealthy for the industry. Many people tried to persuade me to try Ecstasy, and even told me, 'this is the origin of inspiration'," Zhang said.

But rather than winning praise for his propriety, Zhang was pummelled in the state-run press for failing to report the lawbreakers to police. "Instead of protecting his actors, he was appeasing and shielding them. This will only make these movies stars more addicted to drugs," said Eastday, a Shanghai-based news outlet. "If Zhang considered it disloyal to report his friends to the police, he has made a serious mistake, sacrificing the greater good for the sake of his self-interest." The Southern Metropolis Daily wrote a similar commentary headlined "Real love is informing on friends to police," while the Global Times, a nationalist tabloid closely affiliated with the Communist Party, ran a cartoon of a sad star shooting up with a hypodermic needle as Zhang watched from around a corner. "The government wants celebrities to actively shoulder more responsibility" for spreading anti-drug messages, said Pi Yijun, an adviser to the Beijing Narcotics Control Commission. China, he added, is still far less permissive about drug use than America. And censors ensure that drug use very rarely figures in popular Chinese entertainment. A Chinese TV program along the lines of "Breaking Bad" would almost certainly never be approved by authorities - though the American show about a meth-cooking high school science teacher is available online in China and is popular.

"Even President Obama has acknowledged he smoked pot," Pi said. "Although celebrities are a small percentage of China's overall drug users, they are an indicator of the trend. If more celebrities are taking drugs then so are more ordinary people." Los Angeles Times