Social media companies should face the same defamation laws as traditional media outlets, Commonwealth Attorney-General Christian Porter has said.

Key points: Attorney-General Christian Porter wants an even playing field between online platforms and traditional publishers around defamation

Attorney-General Christian Porter wants an even playing field between online platforms and traditional publishers around defamation Like newspapers, sites likes Facebook and Twitter deliver content to audiences and obtain advertising revenue

Like newspapers, sites likes Facebook and Twitter deliver content to audiences and obtain advertising revenue Individual publishers, not Facebook, are currently liable for comments made on Facebook pages they manage

Mr Porter's statement could have major consequences for companies such as Facebook and Twitter, which are used by millions of Australians.

"The playing field between digital platforms and mainstream media is completely uneven," he told the National Press Club in Canberra.

"That is something that needs to be dealt with as urgently as possible as a matter of reform."

Defamation laws allow people and some organisations to sue over comments that damage their reputations.

Mr Porter said any changes to the law would need to "sensibly" take into account the huge volume of material published online.

"Because the volume that goes on Twitter and Facebook is much larger from the volume from a standard newspaper.

"[But] online platforms, so far as reasonably possible, should be held to essentially the same standards as other publishers."

Defamation law is a responsibility of the states, but efforts have been made to create a set of uniform laws.

The Council of Attorneys-General released a discussion paper on defamation in February 2019.

Dealing with defamation

The largest defamation payout to a single person in Australia was awarded this year to actor Geoffrey Rush.

Sydney newspaper The Daily Telegraph is appealing the ruling along with the size of the $2.9 million payout.

Mr Porter described as "very curious" a separate court ruling this year against traditional publishers.

A New South Wales Supreme Court justice ruled that newspapers and broadcasters could be held liable for comments made by members of the public on their Facebook pages.

"That's clearly something that needs to be dealt with," he said.

The civil case was brought by former Northern Territory youth detention inmate Dylan Voller.

Mr Porter said the treatment of online publishers under defamation law was a "very complicated issue" and it would be months before reforms were introduced.

He said other changes would be implemented by the Commonwealth and states by mid-2020.

Facebook and the lobby group representing online players, the Digital Industry Group Inc, declined to respond to Mr Porter's comments. The ABC has also approached Twitter.

The ABC is a member of the Right to Know coalition of media organisations calling for improvements to media and whistleblower laws.