A man who claims to be defamed by Google has now been given the green light to sue the search engine by the High Court.

Milorad Trkulja was shot in the back by an unknown gunman in Melbourne in 2004, at the time of a series of underworld killings.

He wants to sue Google for defamation after discovering that searches for his name brought up images of mob figures due to the shooting coinciding with gangland activity in the city.

The images wrongly linked Mr Trkulja with crime bosses including Tony Mokbel.

Mr Trkulja said he had only ever seen Mokbel on television and in newspapers and the only contact he knew he had had with an underworld figure was a chance meeting with Mick Gatto.

"I was with my ex-solicitor George Defteros, who was also acting at the same time [for] Mick Gatto," he said.

"We were having lunch in Lygon Street and on the way home we passed Mick Gatto sitting there and we just shook hands."

Mr Trkulja's efforts to sue Google had been blocked by a Victorian Court of Appeal decision, but on Wednesday the High Court ruled in his favour.

He said he was "over the moon" with the High Court's decision in his lengthy "David-and-Goliath battle".

A long saga continues

Mr Trkulja first sued Google for defamation in 2012 and won.

He began another proceeding after alleging that defamatory text, autocomplete predictions and images showed him alongside convicted felons when searching phrases such as "Melbourne underworld criminals".

Milorad Trkulja sued Google for search results that wrongfully connected him with crime figures such as Tony Mokbel (pictured).

Autocomplete predictions are the suggestions that appear under the searcher's text before they have finished typing.

A Victorian Court of Appeal agreed with Google that the case had no real prospect of successfully proving defamation.

But in 2017, the High Court granted him special leave to appeal against that decision.

Google tried to stop the High Court case, saying it had not published allegedly defamatory search results, that the search results were not defamatory of Mr Trkulja, and that it was entitled to immunity.

But the High Court on Wednesday found there was clearly potential for defamation.

"There is no evidence here … that it would have been apparent to an ordinary reasonable person using the Google search engine that Google made no contribution to the elements of those search results that convey a connection between Mr Trkulja and criminality," the unanimous judgement said.

"The most obvious, logical connection between the terms of the search and the response, under headings such as 'Melbourne criminal underworld photos', 'Melbourne underworld crime' and 'Melbourne underworld killings', or at least some of them, are criminals or members of the Melbourne criminal underworld."

The court acknowledged the argument by Google's lawyers that some of the images were not criminal figures — including a former Victorian Chief Commissioner of Police and Marlon Brando in his role as the Godfather.

"But in each of the pages on which images of such persons appear, there are also images of persons who are notorious criminals or members of the Melbourne criminal underworld … coupled with images of persons, such as Mr Trkulja whose identity is relatively unknown," the judgement said.

A spokesperson for Google said the company "will continue to defend the claim", but would not comment further on ongoing legal matters.

Case could clear up murky defamation laws, expert says

Legal expert Nicolas Suzor said the decision was exciting, as it might provide clarity on unanswered questions around how defamation laws are applied online.

"At the moment, defamation law — it's a bit of a mess," the Queensland University of Technology associate professor said.

"It's not exactly clear at the moment when an internet publisher will be responsible for removing content that could be defamatory."

He said if the case was to go to trial in the Victorian Supreme Court, the legal system, individuals and internet giants like Google may all get some answers.

"The fact that the High Court has taken an interest here doesn't necessarily mean that Google is going to lose when the full trial goes through," he said.

"What it means is that the High Court is interested enough in this problem to consider it.

"And that's a positive sign because of how difficult and complex defamation law has become in Australia."