Four employees of the Anglo-Australian miner Rio Tinto Ltd. have been arrested over alleged stealing of China's state secrets, the Shanghai state security authorities said Thursday.

The detainees included Stern Hu, general manager of the company's Shanghai office, who was also in charge of the iron ore business in China, according to the Shanghai municipal state security agency.

Hu, an Australian with Chinese origin, was arrested over alleged espionage and stealing of China's state secrets, Stephen Smith, Australian foreign minister, said Wednesday.

The other three, who also worked in the Shanghai office and detained for the same charge, were holding Chinese passports and the case was being investigated according to law, the agency said.

Source: Xinhua