GARDAI held three men for questioning at the weekend in connection with a suspected "guns for hire" operation in Dublin.
Two men were released after being questioned in Lucan for 48 hours under Section 30 of the Offences Against the State Act. An other man, who had been arrested separately, was due to be released late last night.
The arrests follow the seizure of weapons by gardai in different parts of the city. Two guns were discovered during the search of a house in Castleknock on Friday. Weapons were also found in a raid on a city centre premises.
Last week detectives uncovered two rifles, a handgun and ammunition when they raided a boiler house in the grounds of St Vincent's Hospital. A hospital employee has been suspended from duty following the discovery.
The guns were hidden in a wall cavity. Four years ago gardai found some weapons at the same hospital.
A Garda spokesman said the recent arrests were part of an effort to trace the history of the handgun used to murder journalist Veronica Guerin. However, it is not thought any of the weapons recovered was used in the killing.