Prosecutors have taken over the case of four Rio Tinto employees, including Australian national Stern Hu, who allegedly engaged in corporate espionage and bribery, the Wall Street Journal reported. Police handed over the case to prosecutors, who have at least five months to consider whether to bring the case to trial and if further investigation is needed. Rio Tinto has denied any wrongdoing by the company or its employees. Chinese officials have not yet formally charged the employees, who were formally arrested in August 2009. Hu and his colleagues had been detained in June following failed iron ore price negotiations involving Rio Tinto.