In 2013, a report by an archaeologist identified almost 800 possible unmarked graves in Central Otago.
Dr Hans-Dieter Bader, of Auckland, walked over more than 25sq km of ground across 15 cemeteries in Central Otago in May 2012 with a fluxgate gradiometer and a hand-held GPS.
The machine was used to indicate where earth had been disturbed and identify potential unmarked graves.
Dr Bader's report said most of the graves were likely to date from before 1900.
In Clyde Cemetery alone, there were thought to be 138 unmarked graves.
Others with large numbers of possible gravesites included Naseby (93), Millers Flat (90) and Kyeburn Diggings (70).
A 2010 Central Otago District Council document had identified the majority of cemeteries in the district had areas of unmarked gravesites.
Another report by the council's Maniototo property and facilities officer, Janice Remnant, said that created operational issues for cemeteries as large areas were not able to be used for burials.
