Police say that the search for two 17-year-old high school students and their rock-climbing instructor off New Plymouth's Paritutu Rock is now a body recovery mission.

Stephen Lewis Kahukaka-Gedye, Brazilian exchange student Joao Felipe Martins De Melo, known as Felipe Melo, and New Plymouth's Bryce John Jourdain, 42, were out on a rock climbing exercise when they went missing on Wednesday.

The trio were part of a 13-strong group - 11 senior students from Spotswood College and two instructors from the Taranaki Outdoor Pursuits and Education Centre.

Rough seas were pounding the coastline when three students were swept off the rock into the water.

Mr Jourdain jumped into the sea to help the students.

One of the students managed to clamber onto the rocks to safety, but Mr Jourdain, Stephen and Felipe have not been seen since.

On Thursday afternoon police said there was no hope of finding the trio alive and they were now searching for their bodies.

A spokeswoman told NZ Newswire a number of boats were still searching and an Air Force Iroquois helicopter would do a final sweep of the area later on Thursday.

A ground search had been called off but would resume on Friday morning, she said.

The Police National Dive Squad has been unable to assist because of rough seas but remains on standby.

Heavy swells of up to 3m have hampered search efforts, police said earlier.

Felipe's father Celio Fernando Bezerra Melo earlier told Brazilian media that his son had planned to travel home in October.

"We have to pray and hope that everything goes right," Fairfax Media reported him as saying.

One of Felipe's aunts has travelled to New Zealand while the rest of the family are in the northeast Brazilian city of Fortaleza praying, he said.

The other students and instructor were winched to safety off the rocks by the Taranaki Community Rescue Helicopter on Wednesday.