Two mariners in boat off the coast of Taranaki have tested positive for Covid-19.

The mariners are part of a group of nine who had arrived in Auckland on Monday, before being transferred to deep sea fishing vessel in New Plymouth.

Health officials have identified three contacts, who were currently isolating, including two people who worked at the port and a driver who had transported the mariners from Auckland to New Plymouth.

"Health authorities in Taranaki and Auckland will be following up and all three will receive their routine tests while in isolation."

All nine provided negative COVID-19 pre-departure test results before travelling to New Zealand.

The seven other mariners have since returned negative COVID-19 tests.

Health officials say there is a low risk to public health due to standard infection prevention controls.

There were no associated locations of interest at this stage.