One hundred and twelve people have been arrested across 26 countries as part of the probe.
Gardaí searched the homes of five people, and arrested one man.
According to Europol - the agency leading the investigation - some of the most extreme forms of video material was seized, which included babies and toddlers being sexually abused and raped.
'Operation Icarus' is continuing and more arrests are expected.
Europol spokesperson Soren Pedersen said once the material was examined, it was likely more evidence and wider links would be uncovered, and that more arrests were therefore expected.