The Australian newspaper reported Hu and two of his colleagues, Liu Caikui and Ge Minqiang, had conceded their roles in accepting the bribes and faced jail terms of five to 15 years, while the fourth executive, Wang Yong, pleaded his innocence, saying the money was only a loan.

The Australian consul-general in China, Tom Connor, said after the hearing that Hu had “made some admissions about two bribes”

“I can tell you that Mr Stern Hu was accused of receiving two amounts, two bribes. One amount of 1 million [yuan] and another amount of $US790,000 [$A861,223],” Connor reportedly said.

“He did acknowledge receiving some of those two bribery amounts.”

Ge’s lawyer, Zhai Jian, told the Australian all the executives except Wang had admitted the accusations of bribery.

Wang’s lawyer, Zhang Peihong, said his client was claiming that the amount he was accused of receiving as a bribe, $US9 million, was a loan.

It remains unclear where the bribes came from, but Tan Yixin, a senior executive of Shougang Group reported to be close to Hu, was detained on July 7 last year in Beijing for alleged “commercial crimes”, while the China Daily reported last year that Wang Hongjiu from Laigang Group was being investigated for “providing secrets to Stern Hu”

The four Rio executives were arrested on July 5 last year and charged with bribery and stealing state secrets, a charge that was later downgraded to stealing business secrets.

Under Section 163 of China’s Criminal Penalty Law, people found guilty of accepting “extraordinarily huge” bribes can receive sentences of between five and 15 years and the possible confiscation of property.

Chinese lawyers said an amount in the millions of yuan would qualify for this type of sentence. Sentences of up to five years are given for lesser amounts. The charges of stealing business secrets could add up to seven years to any bribery sentences, if the executives are found guilty.