A document published by the Comptroller and Auditor General has stated that the teacher's supervision scheme, which they receive extra payment for, is impossible to monitor and therefore likely to be abused.
At the moment, a teacher receives an extra €1,769 a year, on top of their annual salary, if they agree to carry out supervision during lunchtime breaks or if another teacher is absent.
The Comptroller and Auditor General, whose job is to keep tabs on how public money is spent, says this is costing the State a huge amount of money and should be reconsidered.
However, general secretary of the Teachers Union of Ireland, Peter McMenamin, said the supervision scheme is monitored and is not abused by teachers.
"That [CAG statement] is categorically wrong," he said. "People do keep tabs on it, it does have to be signed off."
"I'm telling you, that within the vocational sector and the community comprehensive sector, it is very tightly monitored."