If any merchandise (other than sea stores or the equivalent for conveyances other than a vessel) is imported or brought into the United States in or aboard a conveyance which was not properly reported or entered, the master, person in charge of a vehicle, or aircraft pilot shall be liable for a civil penalty equal to the value of the merchandise and the merchandise may be seized and forfeited unless properly entered by the importer or consignee. If the merchandise consists of any controlled substance listed in section
1584 of this title, the master, individual in charge of a vehicle, or pilot shall be liable to the penalties prescribed in that section.