Tucci said Kouroumblis had told authorities he would co-operate with the extradition, saying he had exercised his right to remain silent other than to say he was innocent and give his consent for extradition.

His lawyer said Kouroumblis had been told his consent to extradition was now irrevocable.

“I wanted to make sure that he understood what the procedure was that was being followed with regard to him and that he actually wanted to go back to Australia. And he confirmed that to me.”

She said Victorian authorities had 45 days from the date of his apprehension to prepare an extradition application. Homicide squad detectives were expected to travel to Rome from Melbourne as part of that process.

Tucci said Kouroumblis was desperate to speak with his brother, who is in Greece, and had asked her for fresh clothes. She said he remained in good condition inside the packed jail, despite the circumstances.

“He said he was cold. He asked me if he could bring some change of clothes. Because he has no family here, he asked me to help him ... clothes, towels.”

Kouroumblis’ agreement to be extradited could drastically reduce the time it takes for him to face charges and court in Australia.

Contested extraditions can be complex and drawn-out affairs. Once Australian police obtain a warrant for someone’s arrest, they need to prepare a draft extradition request, which needs to be signed off by the federal attorney-general’s office before being sent overseas for consideration.

Kouroumblis first came to light in the Easey Street murder investigation shortly after the crime, when police allegedly found a knife and sheath in his possession that contained traces of blood. Then aged 17, he told detectives he had found the knife on train tracks in Collingwood.

At the time of the killings, he lived just a few hundred metres away from the Easey Street house where the bodies were discovered in January 1977.

About a week after the killings, he was pulled over by police in a routine patrol near Easey Street, and it was recorded in coronial proceedings that he was carrying a knife. He was also named in an inquest into the deaths as the person who found the knife used in the killings but was not called as he could not be located.

In a relaunched 2017 investigation, police identified Kouroumblis as a person who should be re-interviewed and DNA tested. Then aged 57, he agreed to provide a sample – but allegedly left Australia and moved to Greece. It is understood a DNA sample from a relative established a match.

Kouroumblis could not be extradited from Greece, as under Greek law charges must be laid within 20 years of the alleged offence. Attempts through diplomatic channels to have him returned to Melbourne failed, and he was put on an international watch list that led to his arrest in Rome.

Victoria Police has been contacted for comment.

The federal Attorney-General’s Department declined to comment on Wednesday night. A spokesperson for the department previously said the case was being treated as a high priority.

This masthead reported on Tuesday that Kouroumblis had not sought assistance from Australian consular officials. A diplomatic source – speaking anonymously because they were not authorised to discuss the matter publicly – said the Department of Foreign Affairs and Trade was ready to offer it if requested.

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