WA Police Commissioner Chris Dawson has defended the right of police to access the metadata of journalists and blamed an “administrative oversight” for an instance where a reporter’s phone records were examined without a valid warrant.

A Commonwealth Ombudsman report tabled in Federal Parliament this week revealed WA Police twice sought Journalist Information Warrants under new data collection laws from a person who was not authorised to issue one.

Under the legislation, which was introduced in 2015, the special warrants can be issued by an eligible judge or administrative appeals tribunal member but are subject to scrutiny by a public interest advocate who is appointed by the Prime Minister.

Mr Dawson said WA Police had sought warrants in 2016 and 2017 from a judge who had mistakenly believed they could act as the “public interest advocate” for the application under the legislation.

“I’ve got no information to say the police were trying to subvert the law, I would describe it as an administrative oversight that the police, and the judge themselves, thought they were duly authorised to issue the warrant,” he said.

“That process was followed. We thought and the judge themselves thought they were authorised under the new metadata legislation.”

Mr Dawson said he could not reveal specifics of why police sought to access the phone records of the journalist other than that it was part of a criminal investigation. He said he could not reveal who the journalist was or what case the warrants related to.

The records examined included phone numbers, call dates, times and durations — similar to billing records. It did not include the contents of the calls.

Mr Dawson defended the right of police to access the informations, despite criticism it was attack on press freedom.

“It was about information about criminal matters,” he said. “Police have got to do their job and journalists are not above the law. If there is a good reason to investigate an element of criminality then police must do their job.”

Mr Dawson said there was no value obtained from the examination of the metadata and the case was not pursued further.