The latest infections bring New Zealand's confirmed case total to 1169. There are 13 active infections in the country. No cases of community transmission have been detected.
A record number of tests were processed on Wednesday - 10,436 - bringing the overall test total to 368,432.
The three new cases were all detected due to routine testing in managed isolation. The first case, a woman in her 30s, returned to New Zealand from Peru on June 20. She had been staying at the Ibis Hotel in Rotorua and returned a positive result after routine testing on day three of her 14-day managed isolation period. She has been transferred to the Jet Park Hotel, operating as a quarantine facility, in Auckland.