Four Rio Tinto executives have been found guilty of bribery and secrets theft by a Chinese court and all given lengthy jail terms.

Australian Stern Hu was handed a 10-year sentence. Wang Yong was given 14 years, Liu Caikui seven years and Ge Minqiang eight years. The four colleagues were also sacked by Rio Tinto for breaching company policy.

In a statement Rio said it carried out an investigation into the claims when the employees were first arrested but found no evidence of wrongdoing. The company concluded that any illegal activity was conducted outside of its systems.

Tom Albanese, Rio chief executive, said: "I am determined that the unacceptable conduct of these four employees will not prevent Rio Tinto from continuing to build its important relationship with China. This is a high priority for me personally.”

Stern Hu was Rio Tinto’s lead negotiator in talks with Chinese steel mills to try to settle a price for China to buy iron ore from Australian mining companies.

During the trial, the defendants admitted taking bribes, but disputed the amounts of money involved, their lawyers said. According to reports, Mr Hu was charged with accepting bribes of $900k.

The fact that the four had accepted some of the charges led some observers to believe the court may be lenient towards the executives.

The length of the sentences, therefore, came as something of a surprise. Mr Hu was given a seven-year sentence for bribery and five years for commercial secrets theft, reduced to 10 years in total.

Wang Yong was given 13 years for bribery and three for secrets theft, reduced to 14 years in jail. Liu Caikui was given five years for bribery and four for secrets theft, reduced to seven years. Ge Minqiang was handed a six-year sentence for bribery and three and a half years for secrets theft, reduced to eight in total.

All sentences began on 5 July last year when the four were first arrested. They have been detained ever since.