Of the 91 new community cases, 65 are in Auckland.
There are also 39 new cases in MIQ today, with travellers coming from the US, Australia, UK, India, Pakistan, Canada and the UAE.
The ministry's IT team investigated Auckland's case numbers yesterday.
"A suspected issue was reconciled, and the numbers for Auckland for yesterday will remain at 56. There are not a further 40 cases to report today," the ministry said in today's statement.
"In addition, due to the Ministry's daily cut-off period for reporting, we are also announcing out-of-cycle cases for Tairāwhiti," the Ministry said.
The latest numbers bring the seven day rolling average of community cases of 69, and the total number of active cases are 771.
The Ministry said 13,376 booster doses were administered yesterday taking the total to 1,300,364.
Also, 4208 paediatric doses were given on Sunday.
"With Omicron in New Zealand, the best thing you can do is get your booster as soon as it is due."
"Boosters lower your chances of getting very sick and being hospitalised. Being boosted also helps slow the spread of the virus," the Ministry said.
More than 4 million doses of the vaccine have been administered to date to cover 96 per cent of the eligible population.
For Maori, the figure is 90 per cent for first doses, and 85 per cent for second.
The Ministry also said 18 per cent of Maori children aged 5-11 have received their first doses, compared to 34 per cent for this age group across all ethnicities.
No unusual wastewater detections are reported today.
But with recent positive test results in Porirua, the Ministry is urging anyone who lives in Porirua and Wellington's northern suburbs to get a test if they feel unwell with Covid symptoms.
Whole genome sequencing has also confirmed that the case in the Hutt Valley reported yesterday is confirmed as having the Omicron variant.
Public health teams are continuing to manage both Omicron and Delta cases in the community through rapidly isolating cases and contacts, contact tracing, and testing to slow the spread.
The number of active contacts being managed is 8647, and 74 per cent have received calls from contact tracers - while 68 per cent have returned at least one result.
Waikato
There are 17 new cases in the Waikato today, with eight linked to previous cases and seven under investigation.
Nine are reported for Hamilton, four in Morrinsville, one in Cambridge, one in Paeroa. Two remain under investigation," the Ministry said.
Lakes
Three new cases are being reported in Rotorua today. These cases are all household contacts of previously reported Omicron cases.
Bay of Plenty
There is one new case being reported in Tauranga today. The case is a household contact of a previously reported Omicron case.
Tairāwhiti
There is one new case to report in Tairāwhiti today. The case is linked to an existing case and the Soundsplash music festival in Hamilton.
"In addition, there are a further four cases being announced today, which will be officially added to the Ministry's case numbers tomorrow. Three of these cases are also linked to existing cases and the Soundsplash music festival. A further case has investigations ongoing," the Ministry said.
Hawke's Bay
Two new cases are being reported in Hawke's Bay today, both with links established to a previously reported Delta case.
Wellington
The one new case is linked to an event in Auckland. Case investigations are underway to identify exposure events that link to this case.
The update comes as it was revealed Prime Minister Jacinda Ardern tested negative for Covid-19.
Yesterday, 103 new community cases were reported, as well as the news that a person in their 70s had died.
The update advised 56 of the cases were in Auckland, and at least another 40 had been detected but would be included in today's numbers due to a technical glitch.
Of yesterday's 103 new cases, the ministry did not say how many had been confirmed as having the more transmissible Omicron variant.
There is usually a lag before officials can confirm this detail through whole-genome sequencing.
However, it is likely most of the cases are Omicron, considering the variant is more infectious and has rapidly become dominant wherever it has emerged.
New Zealanders have been told to expect cases to double every three days and to assume all recorded cases are Omicron.
The ministry also expected the number of cases linked to the Soundsplash music festival in Hamilton to continue to grow and urged all attendees to seek a test if they had not already done so.
As well as 56 in Auckland, yesterday's cases were spread throughout the country – in Northland, Waikato, Tairāwhiti, Bay of Plenty, Lakes, Hawke's Bay, MidCentral, Taranaki, Wellington and Nelson-Tasman.
There were 288 cases isolating at home in Auckland, with a further 11 in hospital, with an average age of 58. None were in ICU or HDU.
Everyone in New Zealand was asked to act as if Omicron was circulating in their community.
"That means wearing a mask, physical distancing and scanning in using the Covid-19 Tracer app, when you're out and about."
The most common early symptoms of Omicron were a sore or scratchy throat, and a runny nose. People with these symptoms, should get a test, and stay at home until receiving a negative result.
The number of cases linked to the Soundsplash music festival in Hamilton is also expected to grow, with all attendees urged to seek a test if they had not already done so.
