The coalition's plan to have telcos retain the phone and internet records of millions of people will increase the risk of a privacy breach, the Australian Privacy Commissioner warns.
Timothy Pilgrim, who was not consulted before the government announced expanded data retention proposals on Tuesday, says the purview of the policy remains unclear.
"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," he said in an online statement on Friday.
"This data could be considered 'personal information' under the Privacy Act."
He said organisations responsible for holding the information were required by privacy law to protect personal information from misuse and unauthorised access, modification and disclosure.
"It will also be important to consider whether a data retention scheme is effective, proportional, the least privacy invasive option and consistent with community expectations," Mr Pilgrim said.
"Any scheme should also be transparent, accountable and have appropriate independent oversight."