The Ministry of Health said further wastewater samples taken from Tauranga and Mt Maunganui last Wednesday returned negative results for the virus.
That follows negative results from last Monday and Tuesday after the outbreak on the Rio De La Plata ship in Tauranga.
There have been no unexpected detections to report in wastewater samples taken around the country.
Four cases in MIQ yesterday
Yesterday there were four new cases of Covid announced in the country's MIQ facilities although two were historical.
It was also revealed that 10 previously reported cases had recovered since Friday's update.
That brought the number of active cases in New Zealand to 39.
As for the country's historical cases, since January 2021, there have been 119 out of a total of 745 cases. The seven-day rolling average of new cases detected at the border is five.
Two of yesterday's new cases arrived from Australia on August 10, and their infection was picked up on routine day 3 testing.
One of the other cases arrived from the United Kingdom on August 11 via Qatar and Australia, and tested positive on day 1.
The last case arrived on August 12 from Hungary via Germany, also travelling through the United Arab Emirates and Malaysia. They tested positive on arrival.
The two historical cases arrived on August 4 from India and August 10 from Japan. Both of these had been under investigation leading to a delay in reporting.
Meanwhile, across the ditch NSW suffered its worst day of the pandemic on Saturday with 466 new cases and four deaths.
The news saw Premier Gladys Berejiklian unveil a police operation to enforce lockdown compliance across Sydney.
Yesterday the state recorded 415 new local cases of Covid-19 and four deaths.
Meanwhile, as Fiji has a decline in daily case numbers, the country's death toll continued to rise.
Health Secretary James Fong said there were a total of 644 new cases in the 24-hour reporting period to 8am on Friday - down from a seven-day average in July that peaked at around 1200 daily cases.
