A man has been stabbed to death and his body wrapped in a plastic bag before it was dumped in a wardrobe.
Two men and a woman are being questioned over the murder of the 53-year-old, named locally as Christopher Jackson.
The grim discovery was made by gardai after a tip-off to go to the property on Prussia Street in Stoneybatter in Dublin's north inner city on Saturday afternoon.
A Garda source said the body may have been there for a number of days.
It was concealed and stuffed in the bottom of a wardrobe and the killer had planned to move it before gardai moved in, he added.
Detectives are investigating a motive for the knife attack, believed to have centred on a row over money. A post mortem is expected to determine the exact cause of death.
Joe Costello TD, who lives a street away from the murder scene, said the local community is shocked.
"It's a terrible tragedy to have happened anywhere," said the minister of state. "You do not expect it in your own neighbourhood. It's a very settled area with a lot of elderly people here as well as young professionals moving in. It was a total shock to people at Mass."
Mr Jackson had lived at the property with his partner and son.
A man aged in his 30s and a woman in her 40s, who both knew the victim, were later arrested in the city centre and questioned in the Bridewell and Store Street Garda Stations. A second man, also aged in his 30s, was detained earlier and taken to Mountjoy Garda station.