Detectives tonight launched a murder probe after the body of a man was found in a flat.
The grim discovery was made in Prussia Street in Stoneybatter in Dublin's north inner city after a tip-off to gardaí.
A suspect, a man aged in his 30s who knew the victim, was arrested in the city centre and is being questioned by detectives in Bridewell garda station.
It is believed the body had been at the scene overnight but was found shortly before 3pm today.
The scene was cordoned off for a technical examination and the assistant State pathologist, Dr Michael Curtis, confirmed the body was a man.
A post-mortem examination is due to be carried out tomorrow.