The four Rio Tinto employees who have been detained by Chinese authorities since early July have been formally arrested and charged, state media reported. The official charges levied against them include trade secrets infringement and commercial bribery. According to the New York Times, previously released statements on the matter led observers to believe that the detainees, including Australian national Stern Hu, would be charged with espionage, which carries far stiffer penalities and is difficult to defend against. It is unclear whether the charges of violating state secrets laws had been dropped or remained part of a more detailed filing.