19—Legal immunity of authorised persons acting under authority
Where an authorised person does something (whether in this State or elsewhere)
that, apart from this section, would be an offence, the officer or person is
not criminally responsible for the offence if—
(a) the
act is done in the course of acquiring or using an assumed identity in
accordance with an authority; and
(b) the
act is done—
(i)
in the case of an authorised officer—in the course
of his or her duty; or
(ii)
in the case of an authorised civilian—in accordance
with any direction by his or her supervisor under the authority; and
(c)
doing the act would not be an offence if the assumed identity were the
person's real identity.