Gardaí are assisting Spanish police after they arrested 155 people and dismantled an alleged international people smuggling ring.
Spanish authorities suspect the gang of helping Chinese people illegally enter Ireland and the UK.
The arrests come after a three-year investigation in Spain.
Gardaí have confirmed they are working with Spanish authorities in relation to the Irish part of the operation.
155 detenidos que traficaban con ciudadanos chinos a quienes cobraban una "tarifa plana" de 20.000€ por pasaportes falsos y el cruce de fronteras. Los cuatro cabecillas de la red han sido detenidos en #Barcelona https://t.co/dvMcfpdtXs pic.twitter.com/fGA8FZDcZl
— Policía Nacional (@policia) March 13, 2018
Spanish police say the gang picked up the migrants in China and promised to get them to the UK or Ireland in exchange for a “flat fee” of €20,000 per person.
The fee included false passports and assistance in getting across borders.
The migrants were accompanied by guides on their flights to Ireland and the UK and were taught key phrases to help get them through immigration.
The operation was uncovered after five migrants decided to give evidence against the gang leaders and enter a witness protection programme.
Police have said the four leaders of the network have now been arrested. The majority of the 155 people arrested are of Chinese nationality.
They were mainly picked up at Spanish airports.
In addition to the arrests, police confiscated numerous forged documents, computer equipment, mobile terminals, cash and handmade Schengen area entry stamps.