China has suspended all meat imports from an American firm after a banned substance was detected in beef exported into the country, Chinese customs authorities said on Thursday.

Ractopamine, a type of animal feed additive, was detected in a shipment by U.S. company King Meat Service, according to the Chinese General Administration of Customs. 

China will suspend shipment of meat products from the company starting Thursday.

The customs authority said it has notified the U.S. Department of Agriculture about the case.