Concerns from researchers, about the number of people not using the Covid scanner app in Dunedin

A new study in today's New Zealand Medical Journal has looked at who's been scanning in to 40 cafes, restaurants, bars, churches and supermarkets in the southern city.

It found only 10 percent of guests scanned in -- and no one scanned in to a third of the locations.

Otago University researcher Lianne Parkin says the low scanning rate would make contact tracing for an outbreak very difficult.

She says any delays with identifying cases could lead to fatal and serious cases in the community - and more lockdowns which nobody wants