Gardai believe homeless father-of-three Francis 'Frankie' Dunne (64) was murdered and then beheaded after a row over just €80.
Detectives have now made "major progress" with their investigation into the death of the homeless man whose headless and partially dismembered body was found in the garden of a derelict house in Cork on December 28.
It is believed the killing was not planned - and occurred after a dispute over €80 escalated out of control.
Gardai believe Mr Dunne was killed close to where his body was discovered in the property off Cork's Boreenmanna Road at 4pm on December 28.
An Eastern European man left Ireland in the hours after Mr Dunne's death, travelling from Cork to Belfast and then on to Edinburgh.
The man, aged in his late 20s, is then believed to have flown back to Eastern Europe within 12 hours.
Garda enquiries have now revealed that the man had been squatting in properties around Cork in late 2019 after he had a row with his boyfriend and was forced to move out of the apartment they shared.
The man has so far been described as "a person of interest" to detectives.
A team of four Cork detectives flew to Romania in late January and spoke to a man, on a voluntary basis, at a police station in Bucharest.
A key element of the investigation is whether there is a link between the killing of Mr Dunne and the theft of €1,000 from a catering premises in Cork within 24 hours of the murder.
CCTV security camera footage is understood to have played a key role in the probe.
A file will now be prepared for the Director of Public Prosecutions (DPP), who will then decide what action, if any, will be taken in consultation with Interpol and Europol.
Mr Dunne has been described as "a gentleman" who was very quiet and best known for his love of singing.
He had battled an alcohol problem for many years and had been supported by Cork homeless charities.
Mr Dunne's body, which was also missing the arms, was discovered by a neighbour in the undergrowth of the garden on December 28 as they searched for a missing pet.
The missing body parts were later recovered in the garden.
Detectives believe Mr Dunne was murdered after a savage beating inflicted sometime between December 27 and 28.
Mr Dunne's family said no one should have had to endure such a terrible death.
"As Frankie's family, we hope no one else has to suffer the horrendous nightmare of what Frankie endured in the final hours of his life. No one should be left so vulnerable on our streets," they said.
"No one should be beaten or murdered because they find themselves helpless due to alcoholism or for any other reason."
A GoFundMe appeal in honour of Mr Dunne raised more than €5,000 for Cork homeless charities.