Section 189 — Detention of unlawful non-citizens
Text of provision
(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).
Plain English
Section 189 creates a mandatory detention obligation. An officer who knows, or reasonably suspects, that a person in the migration zone is an unlawful non-citizen must detain that person.
The obligation is not discretionary — unlike cancellation powers, the officer has no choice. If the officer has reasonable grounds for suspicion, detention must occur. This has given rise to what is often called Australia's "mandatory detention" policy.
Section 189(3) extends the obligation to offshore areas — officers may also detain persons reasonably suspected to be unlawful non-citizens in an offshore area.
Practical effect
The mandatory detention regime in s 189 has been the subject of significant litigation, including at the High Court (notably Al-Kateb v Godwin (2004) 219 CLR 562, which held that indefinite detention of a stateless person with no prospect of removal was constitutionally valid).
Persons detained under s 189 must be removed as soon as reasonably practicable under s 198, or granted a visa. The detention obligation remains until either event occurs — there is no mechanism for release into the community on bridging conditions under s 189 itself (though bridging visas and ministerial intervention can apply).
Section 4AA requires that the detention of minors be treated as a measure of last resort.