HNZ’s letter said it was directly contacting students and staff who were at highest risk of being infected with measles.
“These people are considered close contacts and may need to stay home to stop measles spreading to others,” it said.
Previously, eight cases of measles have been confirmed and health officials have warned of the risk of an outbreak.
There are locations of interest across the country – in Auckland, Taranaki, Nelson-Marlborough and Tasman, and the Manawatū Whanganui region.
Health New Zealand has not yet directly commented on the case at the college.