In China, four employees of the British-Australian mining giant Rio Tinto have been charged with ‘stealing trade secrets and receiving bribes.’

The indictments—reported through state-run Xinhua news agency—are the latest in a case that has angered the Australian government, and has left Western companies worried about their operations in China.

Among those charged, is China-born Australian citizen Stern Hu. Hu was a lead-iron ore negotiator. After being detained last July, he was held for a month without formal charges, was not allowed to see his family or to contact a lawyer.

A Xinhua news statement alleges the employees had “requested and received” bribes from China’s state-owned steel companies, and that they had solicited trade secrets from those companies through bribery.

Rio Tinto has said their employees have not done anything wrong.

The arrests came during a period of negotiations between the companies, when Rio Tinto had rejected a $19.5 billion U.S. dollar investment from China’s state-owned Chinalco.

A trial is expected to be held later this month, or early March.