A man is being questioned by detectives investigating the murder of another man found with stab wounds in a burnt-out flat.
Michael O Shea, 31, was found by firefighters called to a blaze in North Main Street, Youghal, Co Cork, at approximately 2.30am yesterday.
A man in his late 20s was arrested in the Cobh area of Cork this morning.
He is being held at Midleton garda station under Section 4 of the Criminal Justice Act.
Attempts to resuscitate Mr O'Shea failed and he was pronounced dead at the scene.
Initial inquiries and a preliminary post-mortem examination revealed he had been the victim of a knife attack.
Mr O'Shea's body was brought to Cork University Hospital for a post-mortem examination carried out by assistant state pathologist Dr Margaret Bolster.
Gardai have appealed for witnesses who may have information to come forward.
In particular they want to know Mr O Shea's movements before 10pm on Wednesday and any suspicious or unusual activity around his home over that night.