The three men, including two in their 20s and one in his 40s, were arrested for questioning by gardai when up to 40 officers, supported by armed members, swooped on six properties around Limerick city.
A garda spokesman said today the three men had been “released without charge”.
“A file will now be prepared for the Director of Public Prosecutions in relation to this matter,” they said.
“Investigations are ongoing,” gardai added.
Gardai were analysing mobile phones and documentation seized during searches of six properties in Limerick as part of the probe.