The Australian Federal Police has admitted accessing a journalists’ phone records without a warrant.

Commissioner Andrew Colvin fronted media in Canberra to inform the public of the breach, though the journalist involved has not been informed.

“Put simply, this was human error,” Colvin said.

“It was a mistake that was not picked up and corrected before it occurred by our internal practices and procedures.”

The AFP said the officer failed to comply with new warrant requirements set up in 2015, after Labor said it would not support the data retention bill without them.

The Commonwealth Ombudsman will audit the breach.

Greens Senator Scott Ludlam says the misuse of the metadata retention scheme illustrates the flaws in the mass-surveillance laws of the major parties.

“A scheme that was forced on to the public as a counter-terror tool was instead used in exactly the way we've long feared - in pursuit of a journalist and their source,” said Australian Greens Co-Deputy Leader and Senator for WA Scott Ludlam today.

“Why are the AFP misusing this power to spy on the fourth estate? Why won't they name the journalist or at least inform them they've been illegally accessing their phone records?

“This is the real battle for free speech and accountability in Australia. The Greens and crossbench opposed these laws when they were forced on us by the Coalition and its Labor allies. Now it is time this surveillance regime was overturned.

“A full and independent investigation must be given all the necessary access to swiftly address this breach, and parliament must act to ensure that such violations can never happen again. 

“This kind of information is too dangerous to be so easily accessed, so susceptible to ‘human error’ as the AFP commissioner stated.

“Get a Warrant,” Senator Ludlam said.

Professor Clinton Fernandes from the Australian Centre of Cyber Security says the laws need further reform.

“Under the current laws we're not allowed to know how many journalist information warrants — if any — were even applied for, how many were refused, how many were approved,” he said.

“We are allowed to know that information about other things, like telecommunications interceptions and so on, but when it comes to journalist information warrants, that level of transparency is not available.

“You don't need to tell a journalist that he or she is being investigated. That just defeats the purpose of an investigation.

“What needs to occur is the transparency as to how many warrants were applied for, and of course, how many times has the public interest advocate actually argued against a journalist information warrant. We have no information about that.”