Are there any rules about how the police can use information they get from intercepting phone calls?

In Plain English

Yes, there are rules about how police and other agencies can use information they get from intercepting phone calls and accessing telecommunications data.

Sharing Information: Agencies like ASIC and the NACC Inspector can share intercepted information for their specific permitted purposes. The chief officer of an agency can also share lawfully intercepted information with other agencies if it relates to activities that could harm security or involve a relevant offense.
Using Intercepted Information: Agencies can only use lawfully intercepted information and interception warrant information for permitted purposes related to their functions.
Restrictions: There are restrictions on using information obtained under warrants issued to other agencies, unless it's communicated under specific sections of the Telecommunications (Interception and Access) Act 1979.
Unlawful Interception: If someone suspects that a phone call was illegally intercepted, they can report it to the Attorney-General, the Director of Public Prosecutions, the Commissioner of Police, or other relevant authorities.
Privacy: The Telecommunications Act 1992 (NI) also protects the privacy of telecommunications information, and providing private telecommunications information to another person without proper authorization can result in penalties.
Warrants: Police can apply for warrants to intercept communications or access private telecommunications information, but a judge must be satisfied that certain conditions are met before issuing a warrant.
Human Rights: The use of interception powers must be compatible with human rights, including the right to privacy and freedom of expression. Any limitations on these rights must be authorized by law, reasonable, necessary, and proportionate to achieve a legitimate objective.

Detailed Explanation

The Telecommunications (Interception and Access) Act 1979 and related legislation outline specific rules regarding the use of information obtained through telecommunications interception:

Permitted Use by Agencies: Section 67 of the Telecommunications (Interception and Access) Act 1979 allows officers or staff members of an agency to communicate, use, or record lawfully intercepted information (excluding foreign intelligence, general computer access, data disruption, or network activity warrant information) and interception warrant information for permitted purposes related to the agency. Subsections (1A), (1B), and (1C) outline specific conditions and purposes for using information obtained under warrants issued to other agencies.
Specific Entities: Members of ASIC (Australian Securities and Investments Commission) and the NACC Inspector (National Anti-Corruption Commission Inspector) can deal with lawfully intercepted information and interception warrant information for their permitted purposes, as detailed in subsections 67(3) and 67(3A) of the Telecommunications (Interception and Access) Act 1979.
Communication by Chief Officer: Section 68 of the Telecommunications (Interception and Access) Act 1979 permits the chief officer of an agency to communicate lawfully intercepted information (excluding general computer access, data disruption, or network activity warrant information) and interception warrant information to specific entities like the Director-General of Security, members of the Australian Federal Police, or chief officers of other agencies, under specific circumstances.
Unlawful Interception: Section 71 of the Telecommunications (Interception and Access) Act 1979 addresses situations where a person suspects unlawful interception. It allows the communication of relevant information to the Attorney-General, Director of Public Prosecutions, Commissioner of Police, or other relevant authorities for investigation purposes.
State Authority Requests: Section 69 of the Telecommunications (Interception and Access) Act 1979 allows the chief officer of an eligible authority of a State to request another agency not to communicate information under section 68 to the eligible authority.
Privacy of Information: Section 49 of the Telecommunications Act 1992 (NI) states that a person must not provide private telecommunications information to another person, with exceptions outlined in subsection 49(3).
Warrants: Section 50 of the Telecommunications Act 1992 (NI) allows a member of the Police Force to apply to a Judge for a warrant in respect of the interception of a communication or access to private telecommunications information. Section 51 outlines the conditions under which a Judge may issue such a warrant.
Criminal Law-Enforcement Agency: Section 176A of the Telecommunications (Interception and Access) Amendment (Data Retention) Act 2015 defines criminal law-enforcement agencies and the conditions under which an authority or body may be declared as such.
Human Rights: As noted in the Explanatory Statement for the Telecommunications (Interception and Access-Independent Broad-based Anti-corruption Commission of Victoria) Declaration 2012, the use of interception powers must be compatible with human rights, including the right to privacy and freedom of expression. Any limitations on these rights must be authorized by law, reasonable, necessary, and proportionate to achieve a legitimate objective.
Victoria Police Staff Members: The Telecommunications (Interception and Access) (Staff Members of Victoria Police) Declaration 2023 allows specified Victoria Police employees to be approved to exercise the authority conferred by warrants.