Any property owned under any contract or by any combination, or pursuant to any conspiracy, and being the subject thereof, mentioned in section 8 of this title, imported into and being within the United States or being in the course of transportation from one State to another, or to or from a Territory or the District of Columbia, shall be forfeited to the United States, and may be seized and condemned by like proceedings as those provided by law for the forfeiture, seizure, and condemnation of property imported into the United States contrary to law.