A woman (37) was arrested last night in Limerick in relation to the investigation into the murder of Shane Geoghegan.
She is being held at Ennis Garda station under Section 30 of The Offences Against The State Act.
The latest arrest brings the total in custody to 15.
Seven men and seven women were arrested on Tuesday during a series of early morning raids on properties in counties Limerick, Tipperary and Dublin in a preplanned operation involving more than 70 gardaí. One of the men was released without charge, and a file will be sent to the Director of Public Prosecutions.
On Wednesday evening, another man (in his 20s) was arrested in the Limerick City area in relation to the investigation.
Mr Geoghegan (28) was shot dead on a Limerick housing estate in the early hours of November 9th by gunmen who mistook him for a gangland criminal they were sent to murder.
He was returning home from watching the Ireland-Canada rugby game at a friend's house in the Kilteragh estate, Dooradoyle, just after 1.30am when his killers struck.
The death of Mr Geoghegan caused widespread shock and led to a crackdown on criminal gangs based in Limerick.