Prosecutors in China are proceeding with a court case against four detained Rio Tinto executives, including Australian Stern Hu.

It has been more than six months since four of Rio Tinto's iron ore trading team were taken into custody in Shanghai, facing accusations of industrial espionage.

Until last night there was still some hope in the Rio camp that Hu and his three Chinese colleagues might not have to face a Chinese court and the likelihood of a prison term.

But Chinese prosecutors have decided there is enough evidence to proceed with the case and the Shanghai No. 1 Intermediate People's Court will soon be the scene of a trial which is likely to test Australia-China relations.

But when Liu Caikui, Ge Mingqiang, Wang Yong and Hu go to trial, their hearing will be in all likelihood behind closed doors.

Representatives from Rio Tinto, the Australian Government and even the executives' families are by no means guaranteed access to the trial.

No trial date has been announced but this weekend the traditional Chinese New Year holidays begin, which means the hearing probably will not happen for at least a couple of weeks, at the earliest.

According to court documents, prosecutors will accuse Rio Tinto's iron ore negotiating team of "taking advantage of their position to seek profit for others and asking for, or illegally accepting, huge amounts of money from Chinese steel companies".

The strange thing is that if the men are accused of bribing steel company executives to entice them to hand over sensitive information relating to their company's bottom line in iron ore price negotiations, why would the Rio staff be receiving huge amounts of money instead of just handing it out?

Hopefully when the case moves to a trial some concrete information will be made public about the precise nature of what the men are supposed to have done.

Rio Tinto says its staff are innocent. But according the wire service Xinhua's translation of Chinese court documents, prosecutors say the Rio executives "lured the heads of Chinese enterprises with promises, or through other illegal means, to obtain the steel companies' commercial secrets on multiple occasions, causing extremely serious consequences for the companies".

Last week Rio Tinto appointed a 30-year veteran to the position of managing director for China.

Ian Bauert is a fluent Mandarin speaker who set up Rio's first office in China more than 25 years ago.

He may be walking into a minefield. This year's round of iron ore price negotiations are supposed to be going on at the moment.

Rio Tinto has to keep doing business in China with four of its staff facing lengthy jail terms if they lose in court - and Chinese prosecutors do tend to win these cases.

Financial Services Minister Chris Bowen says the Government is offering Hu the appropriate consular support.

"China is a sovereign nation and has its own legal system; we'll be working within that legal system with his representatives to ensure that he gets whatever assistance is necessary and appropriate from the Government," he said this morning.

"I understand he does have legal assistance in the proceedings, he has legal representation, and I understand our embassy officials have been in contact with those legal officials.

"Of course we would hope this matter gets resolved as quickly as possible, as we have said all the way through."

Editor's note (February 11): Due to an editing error, this story originally incorrectly attributed quotes about iron ore price negotiations and the case against Rio Tinto's executives to Mr Bauert. It has been amended to remove that attribution. The ABC did not speak to Mr Bauert in compiling this report.