Land Search and Rescue says it doesn't have enough volunteers to search for missing people in some parts of the country.
A report on the national volunteer organisation, written by a member of the government's Search and Rescue Council, highlights the search for Fiona Wills, who went missing in rural Hawke's Bay in 2014.
Ms Wills, who suffered from Alzheimer's disease and was 77-years-old when she disappeared, has never been found.
The report suggested that Land Search and Rescue (LandSAR) work with other groups and agencies to make up for any lack of volunteers.
But LandSAR chief executive Steve Caldwell said the organisation already does that, as a matter of course.
"If a search is a significant search, over multi-days, small area, then yes, standard procedure is that we go to neighbouring groups and booster the search teams - that's standard practice."
On its website, LandSAR says it has more than 3000 trained search and rescue volunteers in 61 local groups around the country.
LandSAR volunteers offer specialist land rescue skills free to the "lost, missing and injured" all over New Zealand, through the police and the Rescue Coordination Centre.
It also has 18 specialist teams such as LandSAR Search Dogs, LandSAR Caving, Alpine Cliff Rescue and Swift Water Rescue.