250Detention of suspected offenders

250  Detention of suspected offenders  (1) In this section: suspect means a non‑citizen who:  (a) travelled, or was brought, to the migration zone; and  (b) is believed by an authorised officer on reasonable grounds to have been on board a vessel (not being an aircraft) when it was used in connection with the commission of an offence against a law in force in the whole or any part of Australia.  (2) For the purposes of section 189, an officer has a suspicion described in that section about a person if, but not only if, the person is a suspect.  (3) A non‑citizen detained because of subsection (2) may be kept in immigration detention for:  (a) such period as is required for:  (i) the making of a decision whether to prosecute the suspect in connection with the offence concerned; or  (ii) instituting such a prosecution; and  (b) if such a prosecution is instituted within that period—such further period as is required for the purposes of the prosecution.  (4) Without limiting the generality of paragraph (3)(b), the period that is required for the purposes of a prosecution includes any period required for:  (a) any proceedings in connection with the prosecution; and  (b) the serving of any custodial sentence imposed because of the prosecution; and  (c) the institution of, and any proceedings in connection with, any appeal from any decision in relation to the prosecution.  (5) If the period for which a person may be kept in immigration detention under subsection (3) ends, he or she:  (a) must, unless he or she has become the holder of a visa, that is in effect, to remain in Australia, be expeditiously removed from Australia under section 198; and  (b) may, at the direction of an authorised officer, continue to be detained under section 189 until so removed.