Travellers who bring so-called Fijian "miracle water" into New Zealand are being warned they risk a $400 fine.
Media in Fiji have run stories on the claimed healing properties of water from in the village of Natadradave, in the province of Dawasamu.
Mountain water taken from behind a dam is said to have healed illnesses including conjunctivitis, according to a report last year in the Fiji Sun.
"We have an old dam and during hot weather it dries up and we have to go to the river to fetch water," Natadradave village headman Tomasi Naisoso told the paper.
"People went up to the dam to bath and wash their eye and within days the virus would disappear."
Many people were coming to collect water and the village did not charge them for it, he said.
But the New Zealand Ministry for Primary Industries (MPI) is not impressed with people trying to bring the untreated water to this country and is asking them to stop, if they want to avoid a stiff fine or treatment costs.
"Sourced from a natural spring ... the untreated water is claimed to have healing properties that can cure anything from conjunctivitis to blindness," MPI says.
"Our concern isn't whether the healing properties are real or not, but whether it contains waterborne diseases that could harm New Zealand's freshwater aquaculture and natural environment," said Craig Hughes, MPI's manager north for passengers and mail.
"The locals may call it miracle water, but it is untreated, so it poses a biosecurity risk to New Zealand."
MPI border staff had seized miracle water from nearly 500 air passengers arriving from Fiji since November.
"All arriving passengers are required to declare the water at the border. If they want to keep it, they have to pay for heat treatment, which costs around $60. If they don't declare it, they face a $400 fine or prosecution."
MPI is running a campaign to inform travellers from Fiji about New Zealand's biosecurity rules regarding untreated water. The campaign includes notices at Nadi Airport in Fiji.