Tension has heightened between China and Australia over the detention of four Rio Tinto staff after the Chinese government claimed it had sufficient evidence to support its accusations of bribery and spying. "I stressed that we have sufficient evidence showing that the individuals involved obtained China's state secrets using illegal means. The case has entered the judicial process and I requested the Australian side to respect China's judicial sovereignty," He Yafei, China's vice foreign minister told reporters. Rio Tinto last week said it was "very concerned" about the situation, which has flared up during sensitive negotiations over the price of iron ore for 2009 between producers and suppliers. Rio Tinto has dismissed the allegations as "wholly without foundation". Anger is growing in Australia over the detention of the four, who have now been held for two weeks. Stern Hu, one of those being held, is an Australian citizen and Rio's chief iron ore negotiator. Stephan Smith, Australia's Foreign Minister, said he has asked the Chinese "firmly, but politely" to speed up the process.