If any person offers any goods for sale as having been imported without payment of duty, or as having been otherwise unlawfully imported, then, whether or not the goods were so imported or were in fact chargeable with duty, the goods shall be liable to forfeiture and the person so offering them for sale shall be liable on summary conviction to a penalty of three times the value of the goods or F1level 3 on the standard scale, whichever is the greater, and may be detained.