A second man was arrested yesterday in connection with the murder of Mikolaj Wilk in Cork last year.
Mr Wilk was attacked by a machete-wielding gang at his home at Maglin on June 10.
The 35-year-old father-of-two, originally from Poland, died from shock and haemorrhage due to multiple blows from sharp weapons, in association with a traumatic brain injury, an inquest into his death found.
Initially, a man was arrested in the Cork area yesterday morning and was taken to Togher Garda Station where he is detained under the provisions of Section 50 of the Criminal Justice Act, 2007.
A second man was arrested yesterday evening.
The 30-year-old is detained at Gurranabraher Garda Station, also under Section 50 of the Criminal Justice Act 2007.
He is the fifth person arrested in relation to the investigation.
Gardai made their first arrests in the case in January, arresting three men in their 30s - two in Ballincollig and one in Togher.
Two are from Poland and one is from Latvia. They were all questioned on suspicion of supporting the gang suspected of killing Mr Wilk. All were released without charge with files being prepared for the DPP.
Additional reporting by Eoin English