Shares in Anglo-Australian mining firm Rio Tinto have fallen after China intensified its spying allegations against the company.
China's State Secrets Bureau website said Rio Tinto had spied on Chinese steel mills for six years and helped to inflate iron ore prices.
It said Chinese steelmakers had lost 700bn yuan ($102bn; £61.2bn) through overpaying for imported iron ore.
Rio's shares shed 3.3% after the report was published at the weekend.
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.
Australia has repeatedly sought a quick resolution of the case, in which one Australian and three Chinese Rio Tinto staff have been detained.
China, which detained Australian Stern Hu on 5 July, has told Australia not to interfere in the legal process.
Analysts said the latest development in the Rio Tinto spying allegation case had added to investors' jitters.
"It has to be a concern for anybody marketing anything into China," said Tim Barker, an analyst at BT Investment Management.