The son of actor Jackie Chan has been released from a Beijing jail after completing a six-month sentence for allowing people to use marijuana in his apartment, amid a crackdown on illegal narcotics in the Chinese capital.

A statement issued by Jaycee Chan's entertainment company said the 32-year-old actor and singer left the city's Dongcheng jail a few minutes after midnight local time.

The statement thanked fans and the media for their concern and said Chan would hold a news conference today in order to "apologise and explain".

Police detained Chan, Taiwanese movie star Ko Kai and several other people at Chan's Beijing apartment last August. Chan and Ko tested positive for marijuana, and police seized more than 100g (3.5oz) of the drug. Ko, whose real name is Ko Chen-tung, was released after serving a 14-day administrative detention.

Chan could have been sentenced to as much as three years in prison, but the court showed leniency because he had confessed and showed contrition.

Chan's arrest was a sensitive matter for his father because of Jackie Chan's high profile in China, including serving as an anti-drug ambassador and deputy to the top advisory board to China's legislature. The elder Chan has apologised for his son's actions and said the pair would work together to mend his ways.

A number of celebrities have been caught up in Beijing's drugs crackdown as the city tries to slow ballooning substance use. Police said more than 7,800 people were arrested last summer in Beijing in what was called the biggest anti-drug campaign in two decades.