RTÉ News has learned that Dublin Fire Brigade has been strongly criticised over spending failures at the service.
In the case of more than €490,000 worth of spending, auditors could find little or no sign of any tendering having been carried out, nor were there any proper contracts signed with suppliers.
The criticisms are contained in an unpublished internal report, a copy of which has been obtained by RTÉ's This Week programme.
The report was carried out by the consultancy firm Deloitte for Dublin City Council, and was finalised in recent weeks.
Deloitte examined a sample of spending by the Fire Brigade over a 12-month period, and looked at money paid out by the Fire Brigade to 21 suppliers.
The auditors found problems with more than half of the cases they examined.
The sample included payments to suppliers ranging from as little as €300, right up to some who were paid more than €300,000.
Deloitte identified particular problems in six of those cases, where the spending came to €492,000.
In terms of these six suppliers the auditors found that DFB paid out money to suppliers without any competitive tendering taking place.
This included one payment of €134,000 to one supplier.
Another was just under €100,000.
They also found that once suppliers were chosen, Dublin Fire Brigade also did not agree any formal contract or service level agreement with the supplier - meaning that there was no written deal.
This meant the council would have no formal contract to fall back on in a costly legal dispute, and there would be little or no evidence to contradict overcharging suppliers.
Deloitte concluded that this and the other "control weaknesses" as they called them, exposed the Council and the Fire Brigade to unacceptable reputational damage and risk.
In a brief statement, the council told RTÉ they fully accepted the internal audit report findings.
Procurement expert Dr Paul Davis of DCU Business School, told the This Week programme that the conclusions of the Deloitte report were not surprising given his experience of procurement among public bodies.