It has been 25 years since an Adelaide court found Ivan Polyukhovich not guilty of helping massacre more than 800 people outside a small town in northern Ukraine.

In the early 1990s, 'Polyukhovich' briefly became a household name. He was the first, and remains the only, person to be tried under Australia's amended war crimes act.

While Polyukhovich was one of hundreds of suspected Nazi war criminals who migrated to Australia after World War II, his case is unique.

It has come to occupy a central place in the story of how efforts to bring war criminals to justice in Australia have failed, and continue to fail.

"There is a significant group of such men here in Australia who were drawn like butterflies to a light globe," author and former ABC journalist Mark Aarons said.

"Australia stands almost as a pariah for its failure to take concerted and ongoing action."

Here's a look at how the case unfolded.

An old man charged with murder

In January 1990, Polyukhovich was arrested and charged.

An ID photo of Polyukhovich uncovered during the investigation into his past. ( Special Investigations Unit )

Prosecutors alleged that he was not only involved in the mass execution of Jewish people, but that he had personally murdered other victims during World War II.

At the time he was arrested, Polyukhovich was aged in his 70s, with grey hair and a walking stick. He did not look like the type of person who could shoot men, women and children in cold blood.

But the evidence against him seemed strong.

The case relied both on eyewitness testimony and forensic evidence from a mass grave site, near Polyukhovich's home town of Serniki.

For more than three years, ABC Radio Adelaide presenter David Bevan reported on both the trial and its fallout, and his definitive account, A Case to Answer, has just been republished.

"Here in little old Adelaide, we had worldwide attention on what was going on," he said.

"Eventually three people were charged with war crimes and they were all from Adelaide.

"It was alleged that they had taken part in crimes during the Nazi occupation in eastern Europe."

Excavating a mass grave

To prove the case against Polyukhovich, prosecutors had to first identify the spot near Serniki where the massacre had occurred.

What followed was an endeavour that was both staggering in its scale and harrowing in its detail. Investigators travelled to Ukraine to excavate a mass grave.

David Bevan with his book A Case to Answer, which has been reissued 25 years after Polyukhovich was acquitted. ( ABC News: Daniel Keane )

"With the cooperation of the local Soviet authorities, they cleared a section of the forest and went looking for the pit," Bevan said.

It soon became clear to investigators that they were indeed at the site, and that the killings had occurred during World War II.

"There was evidence given from witnesses that there was a man who had an artificial leg who was taken and killed in the pit that day, and they found a man's body with an artificial leg."

Despite corroborating eyewitness testimony about Polyukhovich's involvement, his defence team was able to pick enough holes in the prosecution's case to secure his acquittal.

Courts not about truth, defence lawyer says

Polyukhovich was eventually put on trial in March 1993. About nine weeks later, on May 18, he walked out of court a free man.

This document showing Polyukhovich and marked with a Nazi stamp was found the day he was arrested. ( Special Investigations Unit )

After retiring to consider a verdict, it had taken the jury less than an hour to find Polyukhovich not guilty.

"It was a patchwork of evidence that the prosecution had to pull together to try and make a case. In the end, it just wasn't strong enough," Bevan recalled.

"Some of the witnesses died before they could give evidence, some of the witnesses weren't well enough to come to Australia.

"Some of the evidence was eroded because, in hindsight, it's clear there were translation problems, and the defence were able to exploit that."

Polyukhovich maintained a public silence about the case until his death in 1997, despite requests from Bevan for an interview.

One of his lawyers, Lindy Powell believes that despite the inevitable disappointment felt by investigators at his acquittal, justice was done.

"People have this notion that courts are about finding truth," she said.

"I am always very wary of thinking about it that way because I don't think that's what the justice system is about."

Polyukhovich was one of many suspected of war crimes

Germany? Austria? No, Australia. The German Club in Adelaide celebrates Hitler's 50th birthday in April 1939. ( National Library of Australia )

Even before World War II, there were concerns about pockets of Nazi sympathy in Australia, especially within the German community.

Newspapers reported on suspected Nazi cells and there were fears of Nazi spies.

But in the years after the defeat of Hitler in 1945, another issue arose, with the influx of Europeans migrating to Australia.

It is believed some had taken part in the Holocaust — the mass killing of Jewish people, Gypsies, democrats, Communists and others persecuted by the Nazi regime and its allies.

"ASIO knew who some of these people were and promptly recruited them and put them on their payroll as agents in their anti-Communist war," Aarons said.

In his book War Criminals Welcome, Aarons documents the names of some of the many suspected mass killers who ended up serving new masters.

He spent hours doing research in archives around the world, gathering details and cross-checking facts.

Despite threats against him, it was his reporting for the ABC during the 1980s that prompted the War Crimes Amendment Act of 1988. His work also led to the creation of the Special Investigations Unit (SIU), a taskforce which helped arrest Polyukhovich in 1990.

"For a very brief period under prime minister Bob Hawke, there was the momentum and the determination to do something about it," Aarons said.

"It was almost a personal crusade."

Two more men charged

Along with Polyukhovich, two other Ukrainians — Heinrich Wagner and Mikalay Berezovsky — were charged following investigations by the SIU.

Adelaide lawyer Lindy Powell defended Polyukhovich during his war crimes trial. ( Supplied: David Bevan )

Only Polyukhovich stood trial and the other cases were later dropped

"It was very ambitious in the late 1980s, early 1990s, to try and bring these men to trial under criminal standards of proof in Australia," Aarons admitted.

"Many of the witnesses had died, many were elderly, the defence lawyers were able to cast doubt on the veracity of their memories."

But even after the SIU was shut down in 1992, stories about war criminals continued to surface in the media.

The case of Latvian Nazi collaborator Konrad Kalejs gained headlines in the early 2000s, while the High Court blocked the extradition of Hungarian Charles Zentai in 2012.

'It will be too late yet again'

Mark Aarons with Maly Elinsohn, who witnessed the murder of her father by Argods Fricsons in July 1941. ( Supplied: Mark Aarons )

Aarons said while he believes there are no longer any Nazi war crimes suspects still alive in Australia, he said there may well be others who committed later atrocities, such as in the Balkans, under Pinochet or during the Soviet occupation of Afghanistan.

"There are a huge number of leads that our investigators could be chasing if the political will was there to give them the resources and legal framework in which to operate," he said.

"One of the critical lessons of our failure to take action against Nazi war criminals was the longer you wait, the more difficult it is to take successful legal action against them."

- David Bevan and Lindy Powell will be part of a panel discussing the Polyukhovich case at the Adelaide Festival of Ideas on July 15.