Crimes (Surveillance Devices) Act 2010

The chief officer of a law enforcement agency, or a person assisting the officer, may issue a written certificate signed by the officer or person setting out any facts the officer or person considers relevant in relation to—

anything done by a law enforcement officer of the agency, or by a person assisting or providing technical expertise to the officer, in connection with the execution of a warrant or in accordance with an emergency authorisation; or

anything done by a law enforcement officer of the agency in connection with—

the communication by a person to someone else of; or

the making use of; or

the making of a record of; or

the custody of a record of—

A document purporting to be a certificate issued under subsection (1) or under a provision of a corresponding law that corresponds to subsection (1) is admissible in evidence in any proceeding.

Subsection (2) does not apply to a certificate to the extent that the certificate sets out facts in relation to anything done in accordance with an emergency authorisation or corresponding emergency authorisation unless the use of powers under that authorisation has been approved under section 29 (Judge may approve emergency use of powers) or under a provision of a corresponding law that corresponds to section 29.

The Surveillance Devices Act 2004 (Cwlth), pt 4 also contains provisions for the use of surveillance devices without a warrant.