Independent Insurance's Irish creditors have formed their own class action group, which will work with the UK's Creditors of Independent Insurance Group (CIIG).
Litigation partners Deirdre Courtney and Susan Stapleton from Dublin-based law firm Ivor Fitzpatrick & Co will represent the group of commercial policyholders.
Courtney said the group was reluctant to reveal the extent of its losses, but said its members came from all areas of commerce, particularly construction and hotels.
"A lot of our clients are now not insured and have very substantial claims against them," she said.
"They're all very badly affected."
Courtney said Ivor Fitzpatrick specialised in corporate investigations and planned to look into the role of insurance regulators in both the UK and Ireland.
"In Ireland, there isn't the same protection and we're really looking at all aspects of how an insurance company can set up a branch in Ireland, yet remain unregulated," she said.
"Under the laws that stand, there are not sufficient safeguards to protect policyholders.
"We want to know how much information was given to the authorities and whether it was correct."
Courtney said the investigations would enable to group to decide which organisations to pursue.
She said the group would carefully monitor to progress of the CIIG.
Class Law partner Stephen Alexander, who is advising the CIIG, said the two groups had met and would benefit from sharing knowledge.
"We've agreed to work together to cover activities on both sides of the Irish Sea," he said.
Alexander said there was a possibility the groups could merge as they came closer to taking legal action.