Australia has urged China to deal with an alleged spy as quickly as possible as his company, mining giant Rio Tinto, rejected claims against him as "wholly without foundation."

Foreign Minister Stephen Smith said he had pressed China "politely but firmly" to push through the case, a day after Beijing angrily told Australia not to interfere.

Smith met China's Vice Foreign Minister He Yafei during a multinational summit in Egypt as tensions rose over the arrests of Australian mining executive Stern Hu and three of his Chinese colleagues.

"When I had my conversation with Vice Minister He I made the point that Australia understood that this was a matter before Chinese legal and potentially judicial processes," Smith told public broadcaster ABC.

"There is a very sharp focus on Mr Hu's role in the 2009 iron ore price negotiations, including possible allegations or suggestions of bribery or receiving unlawfully information from the Chinese side," he added.

Mining giant Rio Tinto rejected accusations that its Australian executive Hu and three Chinese colleagues bribed steel mill officials, charges that China equates with spying and stealing state secrets.

"Rio Tinto believes that the allegations in recent media reports that employees were involved in bribery of officials at Chinese steel mills are wholly without foundation," iron ore chief executive Sam Walsh said.

"We remain fully supportive of our detained employees, and believe that they acted at all times with integrity and in accordance with Rio Tinto's strict and publicly stated code of ethical behaviour."

Rio added that it remained "very concerned" about its employees and said it was still shipping iron ore to China, following reports it was pulling out staff and cutting back exports.

"Rio Tinto continues to operate in China and is maintaining high levels of iron ore shipments from Australia," a statement said.

"Rio Tinto remains very concerned about the four employees detained in Shanghai. The Australian government is keeping the company fully briefed on its efforts to assist them," it added.

Hu, Rio's Shanghai office chief, had spearheaded tough negotiations with China to set annual iron ore contract prices.

Rio last month also walked away from a massive cash injection from China's Chinalco, prompting anger in official Chinese media.

The row over the detained employees escalated this week when Prime Minister Kevin Rudd warned that China's economic interests were at stake, prompting a strong rebuttal from Beijing.

"We are firmly against anyone stirring up the case and interfering with the independent judicial authority of China. This is not in the interest of Australia," foreign ministry spokesman Qin Gang said.

A commerce ministry spokesman on Friday repeated China's position that the case would have no impact on its policy on foreign investments.

"The Rio Tinto case is an individual case and will not affect China's foreign investment policy or change China's foreign investment environment," the spokesman told AFP in Beijing.

Booming China is a huge market for Australia's key resources sector with total trade worth 58 billion US dollars last year.