Australia's privacy watchdog Timothy Pilgrim has warned that indiscriminate metadata collection would place personal information at risk of privacy breaches.

Under the presently broad and opaque proposal, telcos could be required to at least hold data on Australians that would link them to their internet protocol addresses in a move aimed to help law enforcement nail lengthy investigations.

That collected data might be considered to be personally identifiable, and therefore place the holders of it -- be it government agencies or telcos -- at risk of breaching the national Privacy Act, Pilgrim said in a statement.

"At this stage, it is unclear exactly what type of information would be retained," Pilgrim said.

"However, there is the potential for the retention of large amounts of data to contain or reveal a great deal of information about people’s private lives, and that this data could be considered 'personal information' under the Privacy Act.

"The retention of large amounts of personal information for an extended period of time increases the risk of a data breach. Organisations holding this information need to comply with all their obligations under the Privacy Act, including the requirements to protect personal information from misuse, interference, loss, and unauthorised access, modification or disclosure."

He said the privacy interests of Australians was key to the data retention debate and flagged the need to ensure any scheme was "effective, proportional [and] the least privacy invasive option".

It should be transparent, accountable and have appropriate independent oversight, he added.

Precisely what data the Federal Government wants telcos to collect was unclear and the subject of a series of embarrassing bungled explanations by politicians. If telcos were required to capture and store additional metadata, which appeared entirely likely, they would need under Australia's reformed Privacy Act to be able to prove that the information was 'reasonably' secured in the event of a breach.

At minimum, telco and other data fondlers would still be placed at additional risk given the requirement to store already captured metadata for a longer period of time.

Pilgrim was not consulted before the oft-shelved proposal was brought back for consideration. ®