Taranaki District Health Board is working with Port Taranaki to test crew members of a fishing vessel for Covid-19, after they reported flu-like symptoms.
The Spanish-flagged shipping vessel, Playa Zahara, is expected to berth at the port today after applying for permission for a change of crew.
Fifteen of the 18 crew members onboard have experienced a flu-like illness.
The testing will take place in a special area at the port set aside for quarantine and will then depart and remain offshore until results are back on Thursday.
Meanwhile, 15 mariners from another fishing vessel, Viking Bay, have been taken to a quarantine facility in Wellington after testing positive to Covid-19.
One of the crew was confirmed last week to have the Delta variant. No link had been shown between this case and any other cases previously identified in New Zealand, the Ministry of Health said.
Genome sequencing of the 13 other positive test results will begin today.