ADELAIDE, Australia (AP) - China has told Australian officials it is conducting a criminal investigation of Rio Tinto Ltd. employees with a focus on commercial and economic issues rather than espionage, Australia's foreign minister said yesterday.

China detained Australian citizen Stern Hu and three other employees on July 5, as Anglo-Australian Rio Tinto was acting as lead negotiator for global iron ore suppliers in contentious price talks with Chinese steel mills.

State media have said they are accused of bribing executives from Chinese steel mills to get access to industry data, which the Communist government considers secret.

"It's quite clear they are focusing on a criminal or judicial investigation, relating to the 2009 iron ore negotiations," Stephen Smith told Australian Broadcasting Corp. television.

"That is their clear focus, they're not interested in what we would regard as espionage, or national security matters. These are commercial and economic matters, which, under their general definition of state secrets, is included."

The case has strained ties between the two countries, with Australia warning China of the economic repercussions and Beijing telling Canberra not to interfere in state matters.

Mr. Smith, speaking from Jakarta, Indonesia, said Chinese officials have told Australia that their investigation is ongoing and the full details will be known if Mr. Hu is charged.

He said Australia is seeking more details, but Beijing has not been forthcoming.