So far, only the larvae of an exotic mosquito have been found by MPI.

Exotic mosquito larvae has been found near Northland's Kaipara Harbour.

The mosquito, Culex sitiens, is known to transmit Ross River virus and Kinjin virus, as well as Japanese encephalitis in a laboratory setting. It is wide-spread in Southeast Asia, the South Pacific, and Australia.

A spokesman for the Ministry for Primary Industries (MPI) said that if a breeding population of Culex sitiens was found, an eradication programme would "likely" follow.

"MPI has successfully eradicated exotic mosquitos in the past," he said.

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MPI was alerted to the larvae on Friday, and had officially identified its species by Monday.

The spokesman said there was no current risk of contracting diseases spread by the mosquito, "as these diseases are not present here".

MPI officials are investigating how the mosquito may have entered the country.

If you see unusual mosquitos, call the toll-free Mosquito Hotline number 0800 Mozzie (0800 66 99 43).