Australia's opposition party has demanded a parliamentary inquiry into press freedom after police raided a media organisation's Sydney headquarters and a journalist's Canberra home seeking to uncover the source of government leaks.

The government, meanwhile, has defended the nation's potent array of security laws, which have come under fire since the raids last week on Australian Broadcasting Corporation in Sydney and News Corporation Australia reporter Annika Smethurst's home.

READ MORE: Police raid Australian public broadcaster over Afghan leak

Opposition home affairs spokeswoman Kristina Keneally called for the bipartisan Parliamentary Joint Committee on Intelligence and Security to investigate whether the balance between press freedom and national security is right in legislation passed since the conservative government was first elected in 2013.

She wrote in The Australian newspaper that Australia is an outlier among its Five Eyes intelligence-sharing partners United States, Britain, Canada and New Zealand in not having such oversight.

There is also a "concern that only leaks embarrassing the government merit investigation while those that benefit the government do not", Ms Keneally wrote.

Dr Rebecca Ananian-Welsh, a senior lecturer at the University of Queensland Law School, said Australia went from having no counter-terror laws before the 9/11 attacks in the US to having more than any other country in the world, with more than 60 new pieces of legislation and amendments.

There had been no counter-balancing laws to uphold human rights or press freedom, she said. And Australia did not have enshrined rights like the US First Amendment guarantee of free speech.

"We just lack a rights culture," Dr Ananian-Welsh said. "It's there, but it's very weak and has no teeth."

She said taking hard stances on national security had been politically popular and the new laws gave certain government agencies broad powers to do everything from searching metadata without a warrant to co-opting telecommunication workers to crack encryption technology.

She said the raids appeared designed to intimidate potential whistleblowers, sources, and journalists.

But she said she is heartened by the call for an inquiry, and she believes outcry over the raids may help swing the political pendulum back towards protecting press freedoms.

Australia's prime minister and communications minister have been meeting with editors and senior media executives to discuss concerns following the raids, which police have said were based on concerns that secret information had been leaked.

Media organisations say the raids were aimed as much at intimidating the press.

Former defence lawyer David McBride will appear in a Canberra court on Thursday charged with leaking to ABC journalists documents including allegations that Australian troops had been involved in unlawful killings in Afghanistan.

McBride has pleaded not guilty to the charges and argues he acted in the public interest.

The raid on the home of Ms Smethurst, the political editor of Sydney's The Sunday Telegraph newspaper, focused on a 2018 story detailing an alleged government proposal to spy on Australian citizens, which cannot currently be done legally.

No arrests were made as a result of the raids.

Ms Keneally told ABC that the government's "cavalier response" to the raids shows there is a "very real concern that freedom of the press is under attack in Australia".

Communications Minister Paul Fletcher, whose Sydney office was targeted by demonstrators on Tuesday protesting against the raids, did not comment on the likelihood of his government supporting an inquiry as proposed by the centre-left Labour Party opposition.

He said the raids were investigating federal officials for failing to keep information secret, not journalists, and the laws that allowed the search warrants are decades old.

"Of course we understand that journalists are anxious about the events of last week," he told ABC.

"Press freedom is a bedrock principle in a democracy and we are always open to looking at further improvements to the laws if sober analysis of the evidence suggests that is required."