TDs are to investigate how the HSE manages an account containing more than €100 million in money belonging to pensioners.
The Comptroller and Auditor General has highlighted the account, which contains state pension funds for people in nursing homes.
State pensions are paid directly into the fund, with deductions made to cover the cost of their care.
But Comptroller Seamus McCarthy says there is a significant sum of money left in the HSE's account which the agency does not own.
"The total funds at the 31st of December 2014, there's a figure of €136m there - that's actually the property of the patients," he said.