CNN quotes China’s foreign ministry, which claims that it has "conclusive evidence" that four employees of Rio Tinto, the world's second-largest mining company, were involved in espionage against China and that they were stealing Chinese state secrets.

Four employees of the Rio Tinto mining company - one Australian and three Chinese nationals - have been arrested on suspicion of conducting espionage and stealing state secrets. The Australian national, Stern Hu, is the general manager of Rio Tinto's Shanghai office.

CNN quotes a government website: "As understood from the Shanghai State Security Bureau, during China's iron ore negotiation with foreign miners in 2009, Stern Hu gathered and stole state secrets from China via illegal means, including bribing internal staff of Chinese steel companies."

Chinese Foreign Ministry spokesman Qin Gang stated: "Relevant Chinese departments took action against him according to law on the strength of conclusive evidence that he stole China's state secrets on behalf of overseas interests, thereby seriously damaging China's economic interests and economic security."

Stephen Smith, Australia's Foreign Minister stated: "The Chinese state and the Chinese authorities take a much broader view of what state secrets or national security might be than, for example, Australia or other nations might." Smith added that he didn't see wider implications for other companies or individuals doing business in China.