251Powers of entry and search

251  Powers of entry and search  (1) An officer may at any time board and search a vessel if the officer reasonably suspects there is on board the vessel:  (a) an unlawful non‑citizen; or  (b) a person seeking to enter the migration zone who would, if in the migration zone, be an unlawful non‑citizen.  (2) The master of a vessel shall do all things reasonably required by an officer to facilitate the boarding and searching of the vessel by the officer under subsection (1).  (2A) An offence against subsection (2) is an offence of strict liability.  (3) A reference in subsection (1) or (2) to a vessel includes a reference to an Australian resources installation and to an Australian sea installation.  (4) The Secretary or Australian Border Force Commissioner may issue to an officer a search warrant in accordance with the prescribed form.  (5) A search warrant shall be expressed to remain in force for a specified period not exceeding 3 months and ceases to be in force at the expiration of the specified period.  (6) An officer having with him or her a search warrant issued to him or her under this section and remaining in force may, at any time in the day or night with such assistance as the officer thinks necessary, enter and search any building, premises, vessel, vehicle or place in which the officer has reasonable cause to believe there may be found:  (a) an unlawful non‑citizen, a removee or a deportee;  (b) a person to whom a temporary visa has been issued subject to a condition with respect to the work that is to be performed by that person;  (c) any document, book or paper relating to the entry or proposed entry into Australia of a person in circumstances in which that person:  (i) would have become a prohibited immigrant within the meaning of this Act as in force from time to time before the commencement of the Migration Amendment Act 1983; or  (ii) would have become a prohibited non‑citizen within the meaning of this Act as in force from time to time after the commencement of the Migration Amendment Act 1983 but before the commencement of section 4 of the Migration Legislation Amendment Act 1989; or  (iii) would have been an illegal entrant within the meaning of the Act as in force from time to time after the commencement of section 4 of the Migration Legislation Amendment Act 1989 but before 1 September 1994; or  (iv) would have become, or would become, an unlawful non‑citizen; or  (d) any passport or document of identity of, or any ticket for the conveyance from a place within Australia to a place outside Australia of an unlawful non‑citizen, a removee or a deportee; and may seize any such document, book, paper, passport, document of identity or ticket, as the case may be, and impound and detain it for such time as the officer thinks necessary.  (7) For the purposes of the exercise of his or her powers under this section an officer may stop any vessel or vehicle.  (8) An officer may use such reasonable force as is necessary for the exercise of his or her powers under this section.