Gardaí investigating the murder of Mikolaj Wilk in Ballincollig last summer arrested a second man for questioning yesterday.
A man in his 30s was arrested yesterday morning in the Cork area and was taken to Togher Garda Station where he is currently detained under the provisions of Section 50 of the Criminal Justice Act, 2007.
This is the fourth person arrested in relation to this investigation.
Last night a second man, aged 30, was arrested and is being questioned at Gurranabraher Garda Station.
Mr Wilk was attacked by a machete-wielding gang at his home in Ballincollig on June 10 last year.
The 35-year-old father-of-two, originally from Poland, died due to multiple blows from sharp weapons and a traumatic brain injury, according to an inquest into his death.
His wife, Elzbieta, was injured during an apparent attempt to shield him from attack.
Their young children, who were in the house at the time, were not injured in the incident.