Under the act several categories of personnel may stop and ask aviation participant in a security restricted area for their ASIC. In relation to ARO's, most if not all have had to become qualified security guards in order to comply.
Aviation Transport Security Act 2004
The various powers are in the documentation, but here is some of it,
Division 4—Airport security guards
90 Simplified overview of Division
This Division gives airport security guards a limited power to restrain and detain persons. Airport security guards may only detain a person until the person can be dealt with by a law enforcement officer and their ability to use force is restricted.
Regulations must establish requirements to be met before a person can become an airport security guard.
91 Airport security guards
(1) An airport security guard is a person who:
(a) satisfies the training and qualification requirements and any other requirements prescribed in the regulations for airport security guards; and
(b) is on duty at a security controlled airport; and
(c) is not a law enforcement officer; and
(d) is not an eligible customs officer.
(2) The regulations must prescribe the following for airport security guards:
(a) training and qualification requirements;
(b) requirements in relation to the form, issue and use of identity cards.
(3) The regulations may prescribe the following for airport security guards:
(a) requirements in relation to uniforms;
(b) any other requirements.
92 Airport security guards’ power to physically restrain persons
(1) An airport security guard may physically restrain a person if:
(a) the airport security guard reasonably suspects that the person is committing, or has committed, an offence against this Act; and
(b) the airport security guard reasonably believes it is necessary to do so in order to:
(i) ensure that a person who is not cleared is not in a cleared area or a cleared zone; or
(ii) maintain the integrity of a landside security zone, a landside event zone, an airside area, an airside security zone or an airside event zone.
(2) If a person is restrained under subsection (1), the airport security guard may detain the person until the person can be dealt with by a law enforcement officer.
(3) In exercising a power under subsection (1) or (2), an airport security guard must not use more force, or subject a person to greater indignity, than is necessary and reasonable.