The chairman of the Oireachtas Health Committee has expressed his concern at the level of outstanding fees owed to cash-strapped hospitals by health insurance firms.
New figures show hospitals were owed a staggering €196m by insurers in March, compared with €139m the previous year.
The significant amount owed by insurers has led to calls for an overhaul of the claims process system.
The Department of Health has begun negotiations with both the HSE and insurers to address the issue.
And the chairman of the Oireachtas Health Committee, Fine Gael TD Jerry Buttimer, said the issue will need to be scrutinised by his committee.
"It defies logic how this amount of money can be outstanding," he said.
The level of fees are detailed in a letter to the Public Accounts Committee (PAC), seen by the Irish Independent.
The HSE's Chief Financial Officer Stephen Mulvany had told the committee in April that there was "about €150m" outstanding from health insurers.
But he later wrote to PAC clarifying the figure was indeed higher.
"This was my recollection at the time, however, in hindsight I believe I was thinking of the March 2014 figure, which is €139m - the March 2015 figure is €196m," Mr Mulvany said.
"The difference of €57m comprises a €41.3m increase in the level of claims pending by insurers and a €15.9m increase in other claims awaiting payment by the insurers," he added.
The Irish Patients Association (IPA) said last night that the issue of outstanding sums needed to be addressed.
"The HSE needs to get tougher with itself to recover these fees," said IPA Chairman Stephen McMahon.
And Mr Buttimer said it is likely the issue will be investigated by his committee.
"We have to examine how business is being done here. You cannot condone a situation where fees are being left outstanding for so long," he said.
The news comes after the Irish Independent revealed hundreds of surgical operations and specialist appointments will be outsourced to private health providers.
Some patients on public waiting lists may even be sent abroad over the worrying backlog. Beaumont, Connolly and Drogheda hospitals - which have suffered some of the worst trolley gridlock since the beginning of the year - have issued a tender for the work.