COUNCILLORS in Belfast can claim expenses without proof of expenditure such as receipts.
Public spending campaigners said on Sunday night it "beggars belief" and called on Belfast City Council to end the practice.
The Audit Office also said it would consider the issue in its next round of financial audits.
Belfast is the only local authority in Northern Ireland that reimburses expenses even if councillors are unable to provide receipts.
For these claims, councillors fill out a 'lost or unobtainable receipt voucher' which is then approved by a relevant council official.
The 'voucher' scheme relates to expense claims within Britain and Northern Ireland.
Belfast City Council said it is only used in "exceptional circumstances" and otherwise councillors are only reimbursed after producing proof of spending.
However, the local authority was unable to give details of how often the 'vouchers' have been used when asked in a freedom of information request.
It said examining the expense claims would require an "extensive and time-consuming review of its relevant recordkeeping systems" held across several council departments.
The TaxPayers' Alliance criticised the practice.
Its chief executive John O'Connell said: "Most people in the private sector have to submit full receipts to their managers so it's only right that those in the public sector should have to do the same.
"Politicians must realise that money doesn't grow on trees and when public trust in them is at rock bottom because of a litany of expenses scandals involving politicians, these cosy arrangements must be brought to an end."
The council said its reimbursement of expenses to councillors complies with its published scheme, which is based upon local authority regulations.
A spokeswoman said: "This system is designed to take a common sense approach to occasional incidences when receipts are lost or unobtainable, enabling councillors to still claim expenses due to them.
"The council is satisfied that it has appropriate checks and balances in place to prevent misuse of this procedure."
On top of expenses councillors in the north receive an annual basic allowance of about £14,200, with more paid to those with extra responsibilities.
It's not the first time concerns have been raised about councillor expenses in the north.
Last year the Audit Office launched a probe after The Irish News revealed that nine Sinn Féin Derry councillors had their council salaries paid directly into a party bank account.
The account received more than £140,000 annually in allowances and expenses – including one councillor claiming a carer's allowance.
Sinn Féin defended the arrangement, saying some councillors "choose to have their payments paid into a central account and make a voluntary donation to the party".
But in a 'u-turn' all nine Sinn Féin councillors have since changed to instead use individual bank accounts for their council allowances and expenses.
