Man arrested over Easey Street murders is identified - as it's revealed how close cops came to catching suspect decades ago

A man arrested over a double murder in inner-city Melbourne almost 50 years ago has been identified.

Perry Kouroumblis was just 17-years-old when Suzanne Armstrong, 27, and Susan Bartlett, 28, were found dead in their Easey St sharehouse in Collingwood on January 13, 1977.

Now aged 65, Kouroumblis was arrested at Leonardo Da Vinci Airport on Thursday, in the Italian capital Rome, over the slayings that shocked Australia.

It emerged on Sunday that Kouroumblis had been pulled over by the police, who then found a knife in the boot of his car, just two weeks after the killings.

At the time, Kouroumblis lived in Bendigo St, Collingwood, close to the home where Ms Armstrong and Ms Bartlett were killed in what became know as the 'Easey Street murders'.

Ron Iddles, who went on to become a homicide investigator but who in 1977 was just three years on the force, stopped Kouroumblis near the scene of the slayings.

The now retired Mr Iddles found a knife in the boot of the car, which he later gave to detectives, he told the Herald Sun .

He said Kouroumblis did not give him any trouble during the stop and search.

'He was alright because I knew him. I never forgot it,' Mr Iddles said.

'I'd go so far as to say it was a '68 HK Holden.'

The then teenaged Kouroumblis said he had found the weapon at nearby railway tracks under a pedestrian overpass.

Decades later, Mr Iddles looked into the Easey St killings as a cold case, and said the arrest of Kouroumblis was a 'fantastic result for homicide and Victoria Police'.

The suspect, who is a dual citizen of Australia and Greece , had been living in Greece for several years, but could not be detained there to due to a statute of limitations on murder charges.

The police were forced to wait until Kouroumblis left Greece before he could be arrested, Victoria Police Chief Commissioner Shane Patton said.

'There is a 20-year, as I understand, statute bar on initiation of murder charges (in Greece).

'Our warrant wasn't issued within that 20-year period and so it was a matter of waiting, if you like, until he was outside of Greece.

'I don't know the reason why the suspect was in Italy, or was transitioning through or to Rome.

'All I know is that through having the warrants in place, through working with Interpol, the red notice has worked.'

The Interpol red notice, which triggered the suspect's arrest in Italy, included two charges of murder and one charge of rape.

It's unclear why Kouroumblis flew to Rome, but he remains in custody there as Australia starts the legal process to bring him back.

Mr Patton described the murders as 'an absolutely gruesome, horrific, frenzied homicide'.

He said advances in technology, investigative techniques and retracing statements had contributed to the breakthrough.

'This is Victoria's most serious cold case and longest cold case that we have ever solved, and that's why it is such a significant achievement,' the Chief Commissioner said.

'There is simply no expiry date on crimes that are as brutal as this.'

Ms Armstrong and Ms Bartlett were last seen alive on January 10, 1977, and their bodies were found three days later.

Ms Bartlett's 16-month-old son Gregory was found unharmed in his cot.

Their deaths shocked the nation, but no one has been arrested until now.

Victoria Police offered a $1million reward in 2017 to catch those responsible.

The women's families said it was difficult to express their level of appreciation to investigators who tirelessly pursued answers and justice for so long.

'The perseverance and dedication required to achieve the result today is something to truly behold,' they said in a statement on Saturday.

'For always giving us hope and never giving up, we simply say, thank you.'

The women had been at school together in Benalla, in Victoria's high country, and their families said their deaths changed many lives 'irrevocably'.

'We will be forever grateful for the support and understanding shown to us by our friends and family over the past 47 years,' they said.

Mr Patton said though the arrest was an important breakthrough, it was 'just the start of the journey' as the investigation continued.

He said the federal attorney-general would start the process of extraditing the man and Italian courts would set the timeline, but he doesn't expect Australian law enforcement officers to travel to Italy for at least a month.

'We'll need to provide some evidence and there will be detectives from Victoria going over (to) give that evidence to justify the extradition,' Mr Patton said.

Kouroumblis' brother Tony told the Herald Sun the arrest was a 'big mistake'.

'I don't believe he has done anything, I can't believe it,' he said.

'I don't think he was capable of doing anything like that. I think it's a big mistake. We will see what happens.'

Charges against the suspect reportedly cannot be laid until the suspect lands back in Australia.