A large quantity of heroin was found hidden on board a ship in Rotterdam just before the end of the year, authorities at the port said. Police and Customs officers discovered some 439 kilograms of the narcotic hidden below a shipment of talc stone during a routine check. The cargo was still inside a sea container on the ship when it was inspected, police said. Authorities seized and destroyed and destroyed the drugs. No arrests were announced in the case, police disclosed on Friday.