A report released today shows Quinn Insurance lost almost €790m (£658m) last year, but the insurer's administrators insisted the figures are "subject to change", and do not reflect the true state of the business.
The massive losses are revealed in the Financial Regulator's insurance statistical review, and come as efforts intensify to find a new owner for Quinn Insurance Limited (QIL), which went into administration earlier this year.
The company was founded by Co Fermanagh man Sean Quinn as part of the Quinn Group, which also includes property, hotels, and glass works.
The bulk of 2009's losses stemmed from a €677m "extraordinary" charge.
Michael McAteer, one of two Grant Thornton examiners assigned to QIL, last night said that charge related "exclusively" to the controversial inter-group guarantees that pushed QIL into administration.
"Because of the guarantees, we could not include those assets in the regulatory return, but those assets are not gone," said Mr McAteer.
"If we were doing returns for the company's office, those assets would still be there."
Mr McAteer and John McDonagh, QIL private lines and marketing director, insisted the insurer was performing "robustly" and would soon push through premium increases in both the UK and the Republic.
QIL has already put through a 10% increase in the UK on August 31. The duo last night confirmed plans for another "10 to 15%" hike over the next two weeks.
In Ireland, QIL has come under fire from competitors for failing to increase premiums since the administrators took control of the company on April 1.
Mr McAteer yesterday said that rates had been increased in some areas, and reduced in others.
"It's not all about premium - it's about the quality of the business," he said, adding that all business written in the Republic since April 1 was profitable at the core underwriting level.
Mr McDonagh said premiums had been "stagnant" in the Irish market in recent months, despite commentary from other insurers around increasing premiums.
As many as 20 parties are believed to be mulling over a detailed sales prospectus of the QIL business, as investment bank Macquarie hunts down a buyer on behalf of the administrators.