Up to 600 motor insurance policies are to be cancelled after a major Garda investigation.
The force is looking into ghost brokers who have duped thousands of motorists and left up to 10,000 people uninsured on the roads.
Gardaí are working with insurance companies to try to detect policies that were obtained through fraud.
One man has been arrested and charged with theft and fraud offences, and is due to appear in Trim District Court today.
Hundreds of premiums have already been cancelled and Insurance Ireland warned customers to be vigilant when taking out their premium and to check the Central Bank for a list of authorised insurance firms.
A Garda Superintendent warned that ghost insurance brokers are preying on the naivety and inexperience of people unfamiliar with the insurance system in Ireland. He said the criminals involved are particularly targeting non-Irish people.