The Public Accounts Committee said that 40% of all installation visits had to be aborted due NI Water providing the wrong information."The total number of meters installed was 18,000; this equates to two abortive visits for every three installations," the PAC report stated.The weakness in contract management first flagged in 2010, was outlined in a wider Stormont committee probe into the way an internal fraud investigation was carried out.The report looked into the review of suspected fraud involving 'invoice slicing', where an NI Water employee was found to have instructed a contractor to limit the value of invoices submitted for payment to below £20,000.Limiting the value of invoices in this way is regarded as an indicator of fraud.The internal investigation found no evidence of fraud but did find a number of serious weaknesses in management of the contract.The Public Accounts Committee however, found that the investigation was seriously flawed.It found that the investigation did not dig deeply enough and senior management were too quick to close down the investigation based on inadequate and incomplete evidence.It is difficult to understand how NI Water put itself in a situation where it paid this amount of public money for work not to be done.Public Accounts CommitteeThe PAC also reviewed an investigation by the Department for Regional Development into allegations made in 2005 that Roads Service staff had shown favouritism to another contractor over the purchase of road signs.The DRD probe in 2010 found no evidence of impropriety or deliberate partiality by staff.However the Stormont committee again found serious failings in how the investigation was carried out.Chairperson Boyle said: "We were concerned that there was an intolerable delay in investigating the allegations. We were also shocked that over a period of several years, some orders which should have been given to the whistleblower's firm were given to his main competitor, and found it hard to avoid the conclusion that something other than simple error was at play."The Committee admires the whistleblower's dogged determination, over many years, to get to the truth, despite the stress that it has caused him, his family and employees."Ms Boyle said both cases pointed to "fundamental weaknesses in fraud investigation practice"."These deficiencies can only be addressed by ensuring investigations are led by professional investigators with an understanding of relevant laws," she added."The poor quality of these investigations supports the case for establishing a single public sector fraud investigation service."A spokesperson for NI Water said it was inappropriate to comment on such reports, but noted that all relevant recommendations arising from the 2010 report have already been implemented by the company.DRD Minister Danny Kennedy said a number of measures have been introduced in his department and its arm's length bodies to address the issues raised."I fully support the concept of a specialised fraud investigation unit for the public sector and across all departments," he said.