Customs Intelligence and Investigation Directorate (CIID) yesterday   impounded 18 containers of Calcium Carbonate and Limestone at Chittagong port for importing those under false declaration. These goods were imported by Quality Breeders Limited from Vietnam declaring as poultry feed. The importer submitted bill of entry No C1361459 through C&F agent Shadin Enterprise on December 28, 2015 to release it. CIID sent its sample to Laboratory to test and found the goods mixed with l31 per cent imestone and 37 per cent natural calcium carbonate powde, said CIID sources. The total weight of the goods was 504 tones, said Dr Mainul Khan, director general of CIID in a Short Messaging Service (SMS).