Simon Chung, a member of the British Consulate General in Hong Kong, was detained after he was detained in Shenzhen, Guangdong province.

China's media Peng Fei quoted the Luohu Public Security Authority in Shenzhen on Tuesday, saying that Simon Chung was imprisoned for 15 days for violating China's punishment law.

Public security officials said they have guaranteed legitimate rights and interests in the detention period and that Simon Chung acknowledged all the violations.

Earlier, Chinese authorities said that Simon's detention was due to prostitution.

According to the Hong Kong Media South China Morning Post, Simon Chung returned to Hong Kong from a Facebook page where Simon's family also called for release and thanked everyone for their support.

Simon Chung was dismissed on the way back to Hong Kong on a high-speed train after attending an event in Shenzhen on Friday.