China is turning up the heat in a high-profile crackdown on drugs that has ensnared a string of celebrities, including the son of Hong Kong kungfu movie star Jackie Chan, as the government seeks to push forward a wider campaign against extravagance and decadence.Chinese President Xi Jinping has vowed to go after corruption and excess among the elite, a prime source of public discontent as the gap between the poor and the wealthy continues to grow.Actor and singer Jaycee Chan, 32, was arrested in Beijing after testing positive for marijuana, police said on Tuesday, and police found 100 grams of the drug at his home.Police also arrested Taiwan movie star Ko Chen-tung, 23, after a drug test found he used marijuana, Xinhua news agency said.Chan and Ko were arrested in central Beijing after police received a tip-off from residents, the state-backed Global Times reported.The use of drugs in China, particularly synthetic drugs like methamphetamine, ketamine and ecstasy, has grown along with the rise of a new urban class with greater disposable income.Xi has called for a clean-up of the so-called "four practices" of formalism, bureaucracy, hedonism and extravagance. He said in June that China would "harshly crack down" on narcotics, state media reported.Jackie Chan's management company, M'Stones International Corp, issued a statement on behalf of Jaycee saying it was standing by him.Drug-related crimes carry harsh penalties in China including death or life imprisonment in serious cases.Action and comedy star Jackie Chan, 60, served as a goodwill spokesman for the China National Anti-Drug Committee in 2009, state media reported, promoting anti-drug education.China has detained more than 7,800 suspects on drug-related charges this year, up 72 percent from a year earlier, Xinhua reported.Foreign and Chinese patrons of Dos Kolegas, a popular Beijing bar inside a drive-in movie theatre, were spot-tested for drugs earlier this month, according to media reports, resulting in several being detained.State media has frequently referred to drug use as a form of moral corruption damaging society. China had successfully quelled the spread of drugs, particularly opium, since the Communist Party took power in 1949. But the past several years have seen a resurgence in drug use.Last week, a group of 42 entertainment management firms said they had signed a deal with Beijing police that they would not work with celebrities who used drugs, the state-owned Beijing News reported.China has detained a string of other mostly B-list celebrities in recent months on drug-related charges, cases that have been publicised widely in both state and social media. They have included movie and television stars, film directors and a prominent screenwriter.

© Thomson Reuters 2014

China executed two South Koreans convicted of smuggling methamphetamines last week.China's Ministry of Public Security told police across the country to get tough on drugs, gambling and prostitution in February.