Canberra urged Chinese authorities on Thursday to deal “transparently and expeditiously” with the trials of four China-based employees of global miner Rio Tinto accused of bribery and stealing commercial secrets .

“We are not in a position to say when the trial will commence or the duration of the trial. As with all legal processes, it is not appropriate to speculate on the outcome or penalties at this time,” a spokesperson for Stephen Smith, Australia’s foreign minister, said. However, Canberra is expected to receive official confirmation of the trial on Thursday.

China has charged four employees of Rio Tinto with bribery in a move that could complicate efforts to reach a deal in iron ore pricing negotiations and exacerbate tensions between foreign business and China.