SHANGHAI, July 9 (Xinhua) -- Four staffs of the Anglo-Australian mining giant Rio Tinto Ltd. have been detained on charges of stealing China's state secrets, the Shanghai state security authorities said Thursday.

    They 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.

Photo taken on July 9, 2009 shows the Rio Tinto Ltd. Office in Shanghai, east China. Four employees of the Anglo-Australian miner Rio Tinto Ltd. have been arrested over alleged stealing of China's state secrets, including Stern Hu, general manager of the company's Shanghai offic. The four people, including Hu, had been detained by China's security authorities Sunday evening. (Xinhua Photo) Photo Gallery>>>

    Hu, an Australian citizen of Chinese origin, was detained in Shanghai on Sunday on allegations of espionage and stealing state secrets, Australian Foreign Minister Stephen Smith said Wednesday.

    Hu was a long-standing employee of Rio Tinto and had lived in Shanghai for a number of years with his wife, who is also an Australian citizen, he said.

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

    The case was "under investigation" and the related parties would hopefully cooperate positively, said Chinese Foreign Ministry spokesman Qin Gang at a regular press conference Thursday.

    Espionage and the theft of state secrets by the four Rio Tinto employees seriously harmed China's "economic interests and security," Qin said.

    "China will handle the case properly according to law," he said. "This is an individual case and should not be exaggerated or even politicized.

    "We will continue holding a positive attitude on economic and trade cooperation between China and Australia, including cooperation between enterprises from the two countries, which will not only benefit China, but also be good to Australia," he said.

    A statement e-mailed from Rio Tinto to Xinhua Thursday said, "We have been advised by the Australian government of this surprising allegation.

    "We are not aware of any evidence that would support such an investigation."

    Rio Tinto said it would continue to work to support its employees and their families. It refused to comment further on the issue.

    "Rio Tinto intended to cooperate fully with any investigation the Chinese authorities may wish to undertake and has sought clarification on what has occurred," Ian Head, Rio Tinto spokesman said in an email statement to Xinhua Wednesday.

    The iron ore giant is still in talks with Chinese steel mills over iron ore contract prices. The negotiations passed the June 30 deadline as Rio Tinto stuck to its offer of a 33-percent price cut for 2009-2010 contracts, while the CISA insisted on a deeper cut.

    The state-controlled Aluminum Corporation of China (Chinalco) last week bought 1.5 billion U.S. dollars of Rio Tinto shares to cement its 9-percent stake in the miner. The deal came a month after the failure of Chinalco's 19.5-billion-U.S.-dollar bid for a19-percent stake and joint management of some Rio Tinto assets.

    Rio Tinto has representative offices in Beijing, Shanghai and Guangzhou on the Chinese mainland.

A man walks inside the Rio Tinto Ltd. Office in Shanghai, east China, July 9, 2009. Four employees of the Anglo-Australian miner Rio Tinto Ltd. have been arrested over alleged stealing of China's state secrets, including Stern Hu, general manager of the company's Shanghai offic. The four people, including Hu, had been detained by China's security authorities Sunday evening.