Two teenagers have been arrested on suspicion of hacking into the Fine Gael website.
The party's new website was hacked into in January and the details of 2,000 subscribers were stolen.
As part of an ongoing investigation, the Garda Computer Crime Investigation Unit attached to the Garda Bureau of Fraud Investigation, carried out searches at two houses in Birr, Co Offaly and in Galway this morning.
Computers and other media equipment were seized and removed for forensic examination.
Two males aged in their late teens were arrested and are being held at Tullamore and Galway Garda Stations.
During the course of the search in Birr, equipment and chemicals associated with the production of controlled drugs were also seized.
It is understood the arrests are part of a wider international investigation involving police forces in other jurisdictions.
The operation is linked to investigations into the Anonymous group of hackers who have taken down large global websites in denial of service attacks.