The Chinese government's low-key approach to the detention of four Rio Tinto employees showcases its determination to handle the case legally, as well as its desire to establish a fair international commercial environment, a Chinese expert said on Monday.

The latest official response to the Rio case came yesterday as government officials made it clear to Australian Foreign Minister Stephen Smith that Rio executive Stern Hu's arrest is "solely related to a criminal investigation surrounding iron ore price talks, and not necessarily espionage."

The labeling of Hu as a corporate criminal has garnered widespread speculation of whether the Chinese government is about to downplay the Rio case amid a barrage of criticism from high-level Australian officials, including Prime Minister Kevin Rudd and Trade Minister Simon Crean.

Meanwhile, a recent survey in Australia on the Rio case shows most Australians support their government's diplomatic efforts to free Hu, Reuters reported.

"The reason why Australian high-level officials care about the case so much is that the country highly relies on sales of iron ore," said Wan Jun, a professor at the Institute of World Economics and Politics at the Chinese Academy of Social Sciences.

"The Chinese government will handle the case according to the law, which just shows its determination to create a fair and well-legislated commercial environment," Wan said.

"The charges of the case are a matter for the justice department of China, which cannot be interfered with by other departments," he said. "As a result, neither the Ministry of Commerce nor the Ministry of Foreign Affairs have babbled so much about the case as their Australian counterparts."

Rudd, under intense domestic pressure to intervene directly in Hu's arrest, has warned China it has significant economic interests at stake and that the world is watching how it handles the case.

"I also remind our Chinese friends that China too has significant economic interests at stake in its relationship with Australia, and with its other commercial partners around the world."

No charges have been brought against Rio Tinto Group executive Stern Hu, Trade Minister Crean said.

"We don't know what the charges are because the charges haven't been laid," said Crean, who was in China last week.

Hu met with Australian consulate officials and is being treated well and is in "very good health," Crean said.

Crean warned China a week ago to behave like a "market economy," but he added that the unfortunate case won't influence the trade relations between the two partners.

Meanwhile, cash prices for iron ore delivered to China climbed to $91 a metric ton in the week ended July 17, the highest since Oct. 10, according to Metal Bulletin prices for the so-called 63.5 percent grade of material.

Chen Bocang, a lawyer specializing in business law, said Hu's sentence will be according to Chinese law and that he may face possible deportation after serving his punishment on the mainland.

All the four employees were detained at the Shanghai Detention Center on July 5 on charges of spying and it is not known whether more arrests will follow.

Australia has been pressing China over the case and demanded expeditious handling of it.

Rio Tinto released a statement Friday defending its employees, quoting its chief executive, Sam Walsh, as saying, "Rio Tinto believes that the allegations in recent media reports, that employees were involved in the bribery of officials at Chinese steel mills, are wholly without foundation."

Wan, however, begged to differ. "We can deduce that the Chinese government must have already held adequate evidence that Stern Hu broke Chinese law," he said.

"However, the charges can't be easily ascertained because no more details have been published."

Rio Tinto has raked in 400 billion yuan ($58.6 billion) in profits from sales of iron ore on the Chinese market, statistics indicate. Last year alone, its annual returns hit 6 billion yuan ($878.42 million).

But the spying case has cost the mining giant 100 billion yuan ($16 billion), with its market share dwindling by as much as 30 percent, according to a report by the China Times.