Nine people have now died in this country from the coronavirus, with six of them residents of the Rosewood Rest Home in Christchurch.
This is the highest number of deaths in a day in New Zealand.
Director-General of Health Ashley Bloomfield said all four deaths were men, and three were linked to the Rosewood cluster. Two of them were aged in their 80s, and one was in his 90s.
The fourth death was a man in his 70s in Wellington, with that death linked to overseas travel. He was admitted to hospital on 22 March and had been "quite unwell for some time".