A majority of High Court justices on Wednesday found Google was not the publisher of a defamatory article by The Age about a Victorian lawyer, as it was a search engine that only provided hyperlinks to news stories.

"In reality, a hyperlink is merely a tool which enables a person to navigate to another webpage," a joint statement by Chief Justice Susan Kiefel and Justice Jacqueline Gleeson said.

The decision is a huge win for the internet giant, but defamation lawyers have warned it could have ramifications for the general public.

Google took the matter to the High Court after Victoria's Court of Appeal in 2021 refused its attempts to overturn a defamation finding in favour of George Defteros, a lawyer who has represented underworld figures.

The Victorian court found Google was the publisher of a defamatory article by The Age in 2004 because its search results were instrumental in communicating the content to readers.

The US-based search engine argued that providing a hyperlink to a story did not amount to publication and therefore was not defamation.

Google warned it could be forced to censor its search results if the higher court upheld the Court of Appeal's decision, which would have a "devastating" impact on the functioning of the internet.

Five out of seven High Court justices found in Google's favour, ruling it did not help The Age communicate the story to third party users and said the search engine's results "merely facilitated access" to the article.

Justices Kiefel and Gleeson rejected Mr Defteros' claim that search results "enticed" people, finding a search engine user would already be looking for information before the result is received.

Justices Patrick Keane and Michelle Gordon said they would have rejected Google's appeal.

University of Western Australia law professor Michael Douglas said he and his colleagues in defamation law were shocked by the ruling as it could allow Google to get away with inflicting "reputational harm" on Australians.

"The only beneficiaries are massive tech companies, who pay little tax in Australia, and the losers are ordinary Australians who want to defend themselves against horrible things said online," he told AAP.

University of Sydney Professor David Rolph is a member of a defamation expert panel that is advising the NSW's attorney-general about proposed reforms to national defamation law for search engines and social media sites.

He said the finding would help to make a complicated area of the law much clearer.

"The significance here is that you can finely point to what is not considered to be publication for the purposes of defamation law," he told AAP.

Mr Defteros' clients included gangster Mario Condello and underworld identity Mick Gatto.

He was charged, alongside Condello, with conspiracy and incitement to murder Carl Williams, his father and another man, but the charges were later dropped

Mr Defteros successfully sued Google in 2016, arguing its publication of an article by The Age about his arrest on conspiracy and incitement to murder charges had defamed him.

Google was notified of the defamatory article in February 2016, but did not remove it until December that year.

In 2020, Supreme Court Justice Melinda Richards ruled the article implied that Mr Defteros crossed a line from professional lawyer to confidant and friend of criminal elements and ordered he receive $40,000 in damages.

Google has been ordered to pay Mr Defteros' appeal costs.

Australian Associated Press