The Comptroller and Auditor General has concluded that Garda management practices to control the 2017 overtime budget were ineffective, and expenditure significantly exceeded estimates.

The overtime bill for 2017 was €132 million - 12% of the overall pay bill, and three-and-a-half times the overtime cost of €38m in 2014.

A net supplementary estimate of €44.2m was obtained in 2017, mainly for salaries, wages and allowances, including overtime (€10m in 2016).

Overtime is paid to the ranks of Garda, Sergeant and Inspector at 1.5 times the basic hourly rate of pay.

Sundays and public holidays are paid at twice the basic hourly rate of pay.

The C&AG also said there was little detail available about the operational reasons for overtime claimed.

As early as February 2017, the Director of Finance and Services informed the Garda Commissioner and senior management that the overtime spend in the first month of the year was already exhibiting signs of being in excess of budget and that corrective action was required.

The C&AG has said any corrective actions taken to limit overtime costs were unsuccessful and the full year's estimate provision for overtime of €88.5m was exhausted by August 2017.

In the period to the end of the year, overtime continued to be approved and paid without any curtailment.

The C&AG said that while the number of officers receiving overtime between 2014 and 2017 grew by 12%, the total number of overtime hours paid for increased by 219% in the same period.

The average number of paid overtime hours increased by 185% per officer.

Last week, Garda Commissioner Drew Harris issued a directive banning discretionary and administrative overtime as this year's budget of €91m has already run over by €20m.