The Comptroller and Auditor General - the State's financial watchdog - has said there is an inadequate level of information on governance in agencies that are in receipt of almost €4 billion a year in funding from the Health Service Executive.

In its annual report on spending, the auditor says the HSE's own structures also made it difficult to identify who was responsible for monitoring the use of money given to these agencies.

The State's financial watchdog says €3.8 billion was paid by the HSE to about 2,270 agencies to provide a range of health and social care services. That is 28% of the HSE's total budget.

But it and the HSE's own auditor found a number of issues with the way these agencies are run, including non-compliance with procurement rules, public sector pay policies and the absence of internal audit functions.

The HSE is clamping down on the sector, but its own control structures were also criticised by the Comptroller and Auditor General.

The comptroller also criticised the Department of Justice and the Insolvency Service over its computer system for dealing with personal insolvencies.

It was supposed to be highly automated, but the auditor found it required a high degree of manual interventions. It also lacked a project budget.

In three years of operations, the system has had 11 software releases, and the department is now looking for a new system - but that may not be in place until 2019.

Public Accounts Committee Chairman Seán Fleming said the committee was shocked by the auditor's discovery that little more than half of annual social welfare overpayments of €100-€120 million are recouped by the Department of Social Welfare.

The auditor also reported that 13 of the top 100 companies in Ireland have an effective corporation tax rate of less than 1% - mainly due to double taxation relief and research and development tax credits.

The Comptroller and Auditor General said this was because of the use of significant tax credits and reliefs, in particular double taxation relief and research and development tax credits.

In contrast, 79 of the top 100 companies had an effective corporation tax rate of between 10% and 15%.

The report finds 37% of 2016 corporation tax receipts were paid by the top ten taxpayers and 70% by the top 100 taxpayers.

It also found that while Ireland had the lowest statutory rate of corporation tax in the OECD at 12.5%, a study by PwC and the World Bank showed 12 OECD countries had an effective lower rate than Ireland.

In 2016, corporation tax was paid by over 44,000 taxpayers, but receipts were dominated by a small number of taxpayers, mainly multi-national enterprises.

Three sectors of the economy account for around 70% of the total corporation tax receipts - financial and insurance activities; manufacturing (including pharmaceutical manufacturing); and information and communications.

The Department of Finance has pointed out that reliance on a small cohort of large corporation taxpayers is a risk that needs to be carefully managed.

The report by the State's spending watchdog was published this morning.

The Comptroller and Auditor general monitors how public money is spent.

Here are some other findings from the report:

Social welfare overpayments and fraud

The Department of Employment Affairs and Social Protection's overall expenditure of income support payments in 2016 was €19.2 billion.

The number of overpayments on social welfare schemes attributed to fraud in 2016 was 16,225.

From 2013 to 2016, the department recorded overpayments of between €100 million and €120 million annually.

Over the same period, the level of overpayment debt outstanding at year end increased from €420 million to €482 million.

There was some change in the reasons for overpayments between 2013 and 2016:
- 49% of the value of overpayments identified in 2013 was attributed to fraud or suspected fraud. This had fallen to 37% in 2016.
- The proportion of overpayments categorised as departmental error fell from 4.8% to 2.1%.
- There were increases in the level of overpayments attributed to claimant error (up from 34% to 42%) and estate cases (up from 12% to 18%) over the period.

Medical illness and disability claims

The department set a target to carry out one million control reviews in 2016 and has reported that it achieved 95% of this target.

However, significantly fewer medical reviews than planned are being carried out.

Less than 1% of reviews undertaken in 2016 were in relation to the carer schemes (carer's allowance and carer's benefit) where €686 million was spent.

The department achieved less than half of its review target for these schemes.

A fraud and error survey of the carer's allowance scheme is currently under way - this is the first survey of this scheme.

Local property tax

For 2016, five local authorities decided to decrease the LPT by the maximum 15% at a cost of €30.9 million.

Another six local authorities reduced the LPT by between 1.5% and 10%, at a cost of €5.1 million.

No local authority opted to increase the LPT rate in 2016.

Galway's Art House Cinema

The State spending watchdog found public funds committed to Galway's Art House Cinema increased by €2.1 million from the initial expected outlay of €6.3 million.

The Comptroller and Auditor General also found the State bore the financial risks which crystallised when the project ran into difficulties.

It says there was no overall oversight arrangement in place for this project at the outset despite the involvement of a variety of public agencies.

It has recommended the department should review its approach to the projects which are being grant aid, in particular where the key project risks are carried by the State.

It also says early action needs to be taken where projects do not progress as expected or serious shortcomings are identified with the project sponsor.

This includes formal reviews of the project viability, in line with the Department of Public Expenditure and Reform's Public Spending Code requirements.