Australian Prime Minister Kevin Rudd (L) with former US vice-president Al Gore (R) has warned China he is taking a personal interest in the case of a mining executive accused of spying, adding the matter was being closely watched from abroad. (Greg Wood/AFP/Getty Images)
Beijing, at the same time, is insisting the diplomatic wrangle won't effect its trading relationship with Australia, a major supplier of resources such as iron ore and coal.
Mr Hu, a Shanghai-based executive with Rio Tinto, was detained along with three Chinese colleagues, more than a week ago.
They were detained during unusually contentious iron ore talks, accused of spying and stealing state secrets.
Since then it has emerged that a number of Chinese steel mill executives are being investigated.
And on Wednesday a state-run Chinese newspaper reported that Rio Tinto had bribed executives from all 16 of China's major steel mills.
The case has potentially deep implications for Australia's relationship with China. China is Australia's second biggest trading partner and a major buyer of iron ore and coal.
After initially keeping the issue at arms-length, Mr Rudd hardened his approach this week, vowing Australia would always put the interests of its citizens ahead of economics.
He issued a veiled warning to Beijing that it had as much to lose as Canberra if the case wasn't handled appropriately.
"Australia, of course, has significant economic interests in its relationship with China," Mr Rudd told reporters.
"But I also remind our Chinese friends that China too has significant economic interests at stake in its relationships with Australia and with its other commercial partners around the world.
"A range of foreign governments and corporations will be watching this case with interest and be watching it very closely.
"And they'll be drawing their own conclusions about how it is conducted."
Just hours after the prime minister made his comments, Beijing hosed down suggestions the matter would harm its business reputation or trade with Australia.
China's commerce ministry spokesman Yao Jian told reporters China and Australia were very important trading partners and had good co-operation.
"I think these relations will definitely not be affected by an individual case," he said.
He dismissed the suggestion the case would hurt China's business reputation.
"I don't think the Rio Tinto case will affect China's trade environment or foreign investment environment," he said.
Canberra has been hamstrung in its efforts to help Mr Hu because of stonewalling from Beijing, which has only assisted to the letter of a consular agreement between the two countries.
The government has had to glean most information through government websites or public statements from Chinese officials.
The Department of Foreign Affairs and Trade has spoken to or called in the acting Chinese ambassador in Canberra on four occasions. Australian officials in Shanghai and Beijing have made 20 appeals on behalf of Mr Hu to their counterparts in China.
But the opposition insists the government should be doing more.
Opposition Leader Malcolm Turnbull accused Mr Rudd of treating the issue like a low-level consular case.
"I think he's sending a message that he is not deeply concerned about the fact that an Australian citizen has been detained now for 10 days without access to lawyers, without access to his family or his employers," he told reporters.
Mr Turnbull again urged Mr Rudd to pick up the telephone and speak to Chinese President Hu Jintao about the case.
Mr Rudd has indicated his government will make representations at more senior levels about the case, as appropriate.
His strategy appeared to get support from an unusual quarter on Wednesday, when former treasurer Peter Costello indicated the government was following an appropriate process.
"I think as time goes on, the government will get more directly involved in this," Mr Costello said.
"It's starting off cautiously because once the individuals at a very senior level get involved, they're the big shots in the locker."
Mr Rudd said the Australian government had been seeking more information on Mr Hu from the Chinese authorities.
"We'll continue to make the representations that we have in the past and further representations in the future," he said.
"I note the consular agreement, which we inherited from the previous Australian government, limits the demands we can make on the Chinese authorities for consular access.
"For instance, it only entitles the government to have access to Mr Hu once a month."
Access to Mr Hu thus far had been "consistent with the provisions of the agreement", according to officials, Mr Rudd said.
He had spent much of the past two days in "extensive briefings" with senior government officials and the acting foreign minister, John Faulkner, he said.
"We will need to continue to pursue this matter and this case methodically, carefully and patiently and in direct support of Mr Hu's interests. His wellbeing is our primary concern."
Mr Rudd confirmed the government had not received a direct briefing from the Chinese on why Mr Hu had been detained.
"We can simply go to the basis of their public statements ... namely that the Chinese have indicated in their public statements that while he has not been charged they have indicated that he is being investigated on suspicion of espionage and stealing state secrets."
Australia would continue to pursue a broad-based relationship with China, he said.
"It's one where we'll pursue all of our interests simultaneously and that doesn't preclude making representations or international statements about problems of human rights in China.
"I've done so in the past, I'll continue to do so in the future.
"When it comes to prosecuting the interests and supporting the wellbeing of individual Australians abroad, that will be done with full vigour, and will be done with full vigour in the context of the relationship which will be advanced in all of its dimensions but without compromise to the interests of a single Australian."
