The Central Bank has launched an inquiry into the former management at Quinn Insurance.
The bank is to probe whether any members of the former management team at the insurance company broke EU insurance regulations.
In a statement the bank said an inquiry into "suspected prescribed contraventions is a serious matter". The inquiry team will decide whether or not they will hold an oral hearing. The bank did not outline details of the suspected regulation breach
Quinn Insurance was placed into administration in 2010 after it emerged it had breached its solvency requirements by €830m in its 2009 accounts. It was later bought by Liberty.
Taxpayers have had to foot the bill for costs at the insurer through the state-funded Insurance Compensation Fund. Consumers face levies on their premiums for up to 15 years.