A third person has been arrested in connection with the murder of Lee Slattery in Limerick more than 15 years ago.
The woman, aged in her 50s, was detained by gardaí this afternoon.
Earlier, a man and a woman, in their 30s, were arrested.
All three are being held at garda stations in the southern region.
Mr Slattery's body was discovered in Delmege House estate, near Moyross, in May 2010.
The 25-year-old had not been seen for four days after he visited a friend's house in the city on the night of 27 May 2010.
A post-mortem examination established that Mr Slattery had been shot a number of times before being buried.
To date, 27 arrests have been made in connection with the investigation.
Gardaí are appealing to anyone with information to contact Mayorstone Park Garda Station on 061-456980, the Garda Confidential Line at 1800 666 111, or any garda station.
