Troubled mining giant Rio Tinto on Friday publicly backed its four employees detained in Shanghai for allegedly stealing state secrets, saying they had committed no crime and defending their integrity.

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

Some domestic media outlets have reported that executives from all 16 major Chinese mills taking part in intense iron ore price negotiations with global miners this year had received "payments" from Rio employees.

The reports came after the four Shanghai-based Rio employees, including Chinese-born Australian executive Stern Hu, were detained on July 5 for allegedly stealing confidential information during the negotiations.

Hu is the head of Rio's iron ore operations in China, and also the chief of its Shanghai representative office.

China's Foreign Ministry spokesman Qin Gang said earlier there was sufficient evidence that the four stole state secrets and breached national economic security.

Rio said on Friday it fully supported the detainees, and "they acted at all times with integrity and in accordance with Rio Tinto's strict and publicly stated code of ethical behavior."

Rio said it continued to operate in China and was maintaining high levels of iron ore shipments from Australia, after reports said that the company was withdrawing research staff from China and reducing exports after the spy case.

Rio this week reported an 8-percent increase in second-quarter iron ore output and is targeting a record figure this year.

While the firm has a focus on Australia and North America, its activities span the world.

(Shanghai Daily July 18, 2009)