Money was wasted replacing kitchens and windows which had already been changed in Housing Executive properties in Northern Ireland, it has been revealed.
A forensic accounting review into possible overcharging was carried out into the maintenance work of six contractors responding to calls from tenants. Fire doors were fitted when not required and other concerns were raised about the replacement of smoke alarms and handles.
The report said remedial work was carried out and then redone under a planned schedule of maintenance.
It said: "This form of waste needs to be curtailed."
The inquiry was ordered following a similar report on Executive maintenance company Red Sky over claims of substandard work.
The Executive's contract with the firm was terminated in 2011.
Experts compiling the latest report considered the quality of workmanship, whether invoices paid by the Executive were appropriate, whether inspections operated as expected and if there was overcharging or error.
The report said: "VB Evans identified a number of instances where remedial work was carried out and then this work was effectively re-done under a planned works scheme.
"For example, kitchens would be replaced, or be substantially repaired, and then the kitchen would be again replaced. This also happened, but less frequently, with window replacements.
"This form of waste needs to be curtailed. The various departments within NIHE need to examine a sample of instances where this arose with a view to identify what steps require to be taken to eliminate this loss."