Shares in Rio Tinto have fallen after China intensified its accusations of spying by the company.
The State Secrets Bureau website said the mining company spied on Chinese steel mills for six years and helped to inflate iron ore prices.
It said Chinese steelmakers had lost 700 billion yuan ($A122 billion,$US102 billion) through overpaying for imported iron ore.
Rio shares shed 3.3% on Monday following the report.
The report said: "This six-year espionage case involved corruption, information gathering and spying."
Last month, China accused four Rio Tinto workers of stealing state secrets, which the company has denied. They were detained on 5 July.
The security agency also says that a large amount of intelligence and data on Chinese steel companies was found on their seized computers.
Australia has repeatedly sought a quick resolution of the case. But China has told Australia not to interfere in the legal process.
