The raids, which Mr Santow said would be unthinkable in Britain or the US, have attracted international attention of a sort Australia can do without. Britain's new Press Freedom Commissioner, Amal Clooney, said this week that at a time when dictators are mocking the very idea of a free press these actions in a country like Australia sent a bad signal for countries with weaker democratic traditions.

There is no question that the intelligence-gathering powers given to the AFP have helped it apprehend terrorists and keep Australians safe. The Sydney man Isaak el Matari charged last week with planning a terrorist attack and being a member of Islamic State was alleged to have used a range of social media platforms, some open, others encrypted, to communicate about his plans. There is also no question that some information is crucial to national security.

Yet it is worrying if these powers are used much more widely. For example, the whistleblower David McBride, who is alleged to have provided documents to the ABC about alleged war crimes in Afghanistan, was in court on Thursday and questioned why the documents about events 10 years ago on a matter of considerable public interest should still be classified as top secret.

As Nick McKenzie, an award-winning member of our investigative team, pointed out in our recent Please Explain podcast on press freedom, journalism is often about finding out what powerful people do not want us to know and obtaining such confidences can lead both the reporter and their source into a "grey legal area".

Yet the laws the AFP seeks to enforce were created by the legislation of successive governments, in a liberal democracy that – uniquely – does not formally protect press freedom through an explicit charter. Instead, as McKenzie also pointed out, journalists have relied on "inbuilt discretion in our system" to protect them as they go about their work.

Prime Minister Scott Morrison has proposed an inquiry by the parliamentary joint committee on intelligence and security into the balance between press freedom and the intelligence and police agencies' investigative powers, including their use of metadata and search warrants. The Labor Party has said it would like an inquiry that includes whether whistleblowers receive enough protection.

An inquiry is certainly needed but it should be given the widest terms of reference possible to allow it to identify where the threats to press freedom lie and recommend remedies that go beyond tinkering.

• The Herald's editor Lisa Davies writes a weekly newsletter exclusively for subscribers. To have it delivered to your inbox, please sign up here