Six health boards have been reprimanded by the Comptroller and Auditor General over delays in paying arrears to people whose nursing home grants had been wrongly reduced.
Mr John Purcell said the health boards "have questions to answer" and that the affair "has implications for the accuracy of health board accounts".
By June, just over half the arrears had been paid by the six health boards, although money had been provided to them by the Department of Health and Children for the purpose in 1998.
The six health boards are the Midland, Mid-Western, North-Western, Southern, South-Eastern and Western. Only the Midland had cleared the arrears by the end of last year.
The issue arose from the way the six health boards interpreted a rule that people living in nursing homes should be allowed to keep one-fifth of their social welfare pensions for personal use.
The health boards in question failed to apply the rule properly and reduced a nursing home grant towards the cost of living in a home.
As a result, families and individuals paid too much out of their own pockets.
In 1998 the Department gave the health boards £4 million to repay the families and individuals concerned.
Only the South Eastern Health Board paid back some of the monies in 1998. It owed £456,500, and still owed £268,500 at the start of this year.
In 1999, only the Mid-Western Health Board paid anything, with £163,000 still unpaid at the start of this year. The Midland Health Board cleared its debt of £148,378 in 2000. The North Western, Southern and Western health boards paid back some of the money owed.
The slowest payers were the Western Health Board (£526,925 out of £622,432 still owed at the start of this year), and North Western Health Board (£388,090 out of £419,156 still owed at the start of this year). The Southern Health Board owed £100,782 at the start of 2001.
The failure to pay the arrears promptly was the subject of an earlier report from the Ombudsman.
In his subsequent investigation, Mr Purcell found the boards had used some of the money to pay for other services. He also found health boards were inconsistent in how they applied a rule allowing them to "top-up" the grant to chronically sick or disabled people below pension age.
His report can be read at http://www.gov.ie/audgen