It comes after a probe going back five years found unauthorised seven-figure discounts to developers.

A council insider has revealed residential and industrial developments in Estella Rise and Bomen do not have adequate stormwater or rainwater run-off provisions, leaving council vulnerable to being sued by vulnerable neighbours.

A second former mayor, Kevin Wales, has called on senior council staff to stand down while an independent investigation is conducted.

“One person alone could not be responsible,” Mr Wales said.

“Senior planning staff should seriously consider standing down because we cannot have people doing damage to any evidence the investigation is under way.” 

Planning expert Susan Dickerson, who has been battling Wagga council on behalf of a client, said revelations of unlawful planning decisions casts every planning decision into doubt.

“Without perusing the forensic planning reports, and only based upon the information the general manager has provided to the public, along with the inference of a possible ICAC investigation, this brings concerns to light with regards to the legalities of all previously issued development approvals,” Ms Dickerson said.

“With extensive experience in the planning arena I have found my dealing with staff here to be difficult. 

“Professionally, I have found additional obstacles that applicants had to hurdle over that were not based on good planning grounds.

“It is also noted that many documents and policies are out of date and should no longer be able to be relied upon.”

The town planner said the planning department lacked “clear direction and leadership for some time”.

Council’s planning department lost its most senior bureaucrat eight months ago when director of planning and regulatory services Andrew Crakanthorp was stood down following undisclosed allegations levelled against him.

Wagga council had promised it would have reviewed substantial sections of the key planning documents – Local Environment Plan (LEP) and Development Control Plan (DCP) –  by 2015 but it now tentatively expects the review to be completed by early 2018.