BEIJING: Chinese investigators have asked for permission to arrest a number of local steel executives suspected of handing commercial secrets to mining giant Rio Tinto, state media said Wednesday.

The report in the Procuratorial Daily came as state media said prosecutors had formally approved the arrest of Stern Hu and three other Rio Tinto employees on charges of "trade secrets infringement and bribery."

"Investigators have recently filed applications with the prosecutor's office for permission to arrest Chinese steel executives suspected of providing commercial secrets to Hu and others," the paper said.

The paper did not identify the Chinese suspects or provide any other details.

Hu's arrest along with his three Chinese colleagues followed Anglo-Australian mining giant Rio's snubbing of a proposed 19.5-billion-dollar investment from China's state-owned metals giant Chinalco, raising speculation the events were linked.