A woman is being questioned as part of an investigation into the death of Vincent Maher in Finglas, Dublin, last week.
The 23-year-old was arrested earlier this afternoon and is being held at Finglas Garda Station.
Another woman, who was arrested on Friday, was released from garda custody without charge this afternoon.
A file is being prepared for the Director of Public Prosecutions.
Mr Maher's body was found at an apartment on Wellmount Road in Finglas in the early hours of last Saturday morning.