According to the New York Times, at least seven Chinese steel industry executives have been detained by the Chinese authorities in what appears to be a broadening corruption investigation connected to last week’s arrest of four employees of the giant mining company Rio Tinto on espionage suspicions.

According to Chinese government websites, the initial investigation, which began with accusations that four Rio Tinto workers (one Australian and three Chinese nationals) had stolen state secrets, has widened. The investigation has reportedly revealed widespread bribery in business dealings. The Chinese authorities now believe that the four Rio Tinto employees paid for detailed government trade and manufacturing information in order to obtain an edge in iron ore negotiations with Chinese state-controlled steelmakers.

The New York Times quotes experts on China’s steel and iron ore industry who claim that corrupt practices have been rife for years, including the exchange of confidential market data that Beijing now claims are state secrets.

China is the world’s largest producer of steel; giant mining company Rio Tinto is one of its biggest suppliers of iron ore.

In the meantime, Australian officials have requested that the case be expedited. Beijing has officially been closemouthed about the case. Nevertheless, in an article published yesterday in the state-controlled newspaper The Beijing Morning Post, it was reported that senior managers from five steel companies were being questioned about illegal activities.