Dunedin City Council parks and reserves manager Lisa Wheeler said the council was working to find a way to identify the unmarked graves before it started the first stage of its development plan for the cemetery.
The council had been unsuccessful in attempts to locate the graves and was investigating the use of ground penetrating radar, she said.
''So when we do some of the development work, and put some landscaping in, we are not encroaching over any unmarked graves.''
The council was aware of a ''pocket'' of unmarked graves in the cemetery and a broad grave search could reveal more, Ms Wheeler said.
''I want to be absolutely certain there are no other areas that we are unaware of before we start moving forward.''
The timeline for the first stage of the development plan was June 30, she said.
