Gardai have sealed off a house at Mourne View in Skerries, north county Dublin, after a man was stabbed to death.
The incident took place shortly after 6pm.
Gardai believe the killer was known to the victim.
Shortly after the body was found, officers attempted to gain access to a house nearby to interview a man but could not get in.
Following negotiations, however, they were allowed into the house.
A suspect was subsequently arrested and taken for questioning to Ballymun garda station.
He was being held last night under section 4 of the Criminal Justice Act, which allowed gardai to detain him without charge for up to 24 hours, excluding rest periods.
Gardai have recovered a knife, which they suspect was used in the stabbing.
But no arrest has yet been made.
The dead man is believed to be 55 years old.
The area remained sealed off pending a forensic examination of the scene by members of the technical bureau from Garda headquarters in the Phoenix Park.
Officers have also notified the office of the State Pathologist.
It is the second stabbing in the capital within the past 24 hours.
A 21-year-old man was left with a gaping wound in his stomach after he was slashed by a Samurai sword during a party at a house in Firhouse in south county Dublin early this morning.
The victim later underwent emergency surgery at St James’ hospital after he had been taken there by ambulance in a critical condition.
Gardai recovered a sword believed to have been used in the attack in a garden at the back of the house.
Officers arrested a 21-year-old suspect at the scene and he s being held for questioning at Tallaght station