# Detention of unlawful non-citizens

> act-s189 — as in force on 2026-06-04 — C2026C00232 · Compilation No. 171 — https://www.legislation.gov.au/C2026C00232/latest/text

189 Detention of unlawful non-citizens
          (1) If an officer knows or reasonably suspects that a person in the
              migration zone (other than an excised offshore place) is an
              unlawful non-citizen, the officer must detain the person.
          (2) If an officer reasonably suspects that a person in Australia but
              outside the migration zone:
                (a) is seeking to enter the migration zone (other than an excised
                    offshore place); and
                (b) would, if in the migration zone, be an unlawful non-citizen;
              the officer may detain the person.








          (3) If an officer knows or reasonably suspects that a person (other than
              a person referred to in subsection (3A)) in an excised offshore
              place is an unlawful non-citizen, the officer must detain the person.
        (3A) If an officer knows or reasonably suspects that a person in a
             protected area:
               (a) is a citizen of Papua New Guinea; and
               (b) is an unlawful non-citizen;
             the officer may detain the person.
          (4) If an officer reasonably suspects that a person in Australia but
              outside the migration zone:
                (a) is seeking to enter an excised offshore place; and
                (b) would, if in the migration zone, be an unlawful non-citizen;
              the officer may detain the person.
          (5) In subsections (3), (3A) and (4) and any other provisions of this
              Act that relate to those subsections, officer means an officer within
              the meaning of section 5, and includes a member of the Australian
              Defence Force.
               Note:      See Subdivision B for the Minister’s power to determine that people
                          who are required or permitted by this section to be detained may
                          reside at places not covered by the definition of immigration
                          detention in subsection 5(1).