Chinese police are investigating a chemical trafficking case with the collaboration of US law enforcement authorities, the Ministry of Public Security said on Friday.

Police in central Hubei Province are probing the case based on leads provided by the US side, said a statement issued by the ministry, adding that suspects of the case exploited differences in regulating chemicals and engaged in activities related to cross-border trafficking and illegal foreign exchange transactions.

Four suspects, including a 38-year-old man surnamed Gao, have been caught, and a company Gao operated has been terminated, the statement said.

It added that the investigation has not yet concluded.