Rotorua Lakes Council has engaged a private investigator to help ensure confidential information is not leaked to the public or media in the future.
The move has been described as "overkill" by one councillor, but others support the decision.
Late last year a confidential council paper was leaked to members of the Rotorua District Residents and Ratepayers group.
It contained sensitive information and costings regarding the council's controversial plan to build a "New Zealand first" shared library and children's health hub facility - a joint project with the Lakes District Health Board.
In a written statement to the Rotorua Daily Post yesterday, Craig Tiriana, manager of the council's chief executive's office, said Rotorua-based security consultants Private Investigations Ltd had been engaged to assess the council's "current policies and practices and to enhance them where appropriate".
Private Investigations Ltd is owned and operated by former New Zealand police officer Mike Dingwall. According to his website, Mr Dingwall is a licensed private investigator and security consultant specialising in, among other things, employment investigations and corporate or business theft or dishonesty.
Mr Tiriana said the contract would cost an estimated $16,000 plus GST (a total of $18,400).
"To date this organisation has not been provided any further information on the source or sources of any leaks. However, because this type of smear has the ability to affect the way some people view their working relationship with Rotorua Lakes Council ... this review was determined necessary to ensure council is treating confidential information appropriately."
Mr Tiriana said initial work was carried out by the company last month.
"The second phase is to review that work, revise and amend structure, then embed policies and procedure. This should be completed across the next month."
Councillor Glenys Searancke, the chairwoman of the Rotorua District Residents and Ratepayers group, said in her view the review was not necessary. "I think it's absolute overkill. This sort of thing goes on all the time and has for years."
But councillor Mike McVicker supported the move. "I'd like to get to the bottom of the issue once and for all and this needs to be resolved," he said.
Councillor Charles Sturt agreed, saying he would like to know who leaked the information, but either way the handling of confidential information had to be more secure.
Mayor Steve Chadwick backed the move.
"I'm supportive of what the executive has done. It will give investors and the community confidence that they can trust us with their confidential information. This is about having a robust and professional organisation which means when they share something with us, that information is safe."