European Union cartel busters have switched their attention to motor insurance brokers operating in this market.
It comes after a dawn raid on Tuesday at Insurance Ireland, the representative body for the sector.
One of the largest insurance brokers in the market, Marsh Ireland, has now admitted it was raided.
But another broker, Aon, refused to comment on reports it was the subject of an unannounced swoop.
It is understood firms that have been raided this week have been given legal advice not to admit they are subject to a swoop.
Advice issued by law firm A&L Goodbody states: "Do not issue a press release or comment publicly on the dawn raid unless it becomes public knowledge.
"Advise your staff that confidentiality is imperative in this situation and do not disclose the dawn raid to any third party."
Commission officials are here for at least a week, investigating allegations of cartel activity in the motor insurance industry. They may also return later.
They are turning up at offices demanding to seek named executives and taking mobiles, laptops and desktops. Most insurance companies have denied they have been raided by the European Commission Competition Directorate officials, accompanied by Irish competition enforcers.
The denials come despite the EU Competition Commission, headed by Margrethe Vestager, saying on Tuesday it was carrying out raids on motor insurers.
In a statement, it said it was carrying out "unannounced inspections at the premises of companies active in motor insurance in the Republic of Ireland".
A spokeswoman for the commission said it was unable to name the companies and organisations it raided.
Insurance Ireland maintains its database is available to all market entrants.
A cartel is a conspiracy against consumers to keep prices artificially high. A cartel usually means restricting new entrants to a market. Motor premiums have been going up by as much as 70pc at times over the past three years.
It is understood various databases with details about drivers and their claims history are the focus of the raids, with claims new entrants cannot get access to these databases.
The raids come as the Competition and Consumer Protection Commission is already involved in a probe into alleged cartel activity in the insurance industry.
Last year, Zenith Insurance stopped offering car coverage in this country. At the time it was the largest Gibraltar-based motor insurer here.
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