The highly sensitive trial of four employees of the Anglo-Australian mining giant Rio Tinto has opened in Shanghai,
One media report says that one of them, Australian citizen Stern Hu, has already pleaded guilty to bribery charges.
The former head of Rio Tinto's Shanghai-based iron ore negotiating team is said to have received around $1 million in bribes.
Hu and his Chinese colleagues - Liu Caikui, Ge Mingqiang and Wang Yong - also face charges of offering inducements to Chinese steel companies in order to receive sensitive commercial information.
That part of the trial will be heard in secret, the ABC reports, despite the Australian government's requests for diplomats to be allowed to watch all of the hearing and reporters to observe even a small part of it. All requests were denied by Chinese officials.
The ABC also applied for permission to report on the case, but was refused.
The world is watching - Rudd
Prime Minister Kevin Rudd, meanwhile, has repeated his call for China to ensure a fair trial. "The world will be watching very closely how this trial is handled," he says.
The case has strained ties with Canberra and fuelled concerns about doing business in China.
Rio Tinto's chief executive Tom Albanese says the trial is of major concern to the company, one of the principal suppliers of the natural resources China needs to sustain its economic boom.