Gardaí investigating the murder of Shane Geoghegan in Limerick last year have arrested 12 people.
Six men and six women were detained this morning following searches in Limerick and Dublin.
They are aged from their teens to their 40s and are being questioned at garda stations in Limerick, Dublin, Tipperary and Clare.
They are currently being held under Section 30 of the Offences Against the State Act and can be held for up to 72 hours.
The 28-year-old was shot dead in Dooradoyle in November in what Gardaí believe was a case of mistaken identity.