A positive Covid-19 case visited an Auckland Pak'nSave supermarket last weekend, staff have been told.
The person shopped at the Royal Oak supermarket on Saturday August 8, between 1pm and 3pm.
The store is still open but those in the shop at the time are asked to watch for symptoms of Covid-19.
Royal Oak Pak'nSave manager Michael Van Brink told staff in a letter yesterday they were "very unlikely to be affected by this brief exposure" and that those working at the time would be considered casual contacts of the case.
"The person did not know they were infected at the time," he wrote.
Staff working while the infected person shopped there have been told they do not need to go in to self-isolation as a precaution, as the visit has been deemed "low risk" by the Auckland DHB.
"Your safety and wellbeing is our top priority and I understand there will be a range of reactions to this casual contact," Van Brink wrote.
Management would make sure staff had all of the information and support they needed.
"Thank you so much for all you are doing to help our community with their grocery needs during these challenging times."
A spokeswoman said the person was not symptomatic at the time and public health considers employees and shoppers also in the store at this time to be at low risk.
As a precaution, those in the supermarket on Saturday afternoon between 1pm and 3pm should continue to adhere to Auckland's alert level 3 restrictions and watch for the signs of Covid-19.
Thirteen new cases of were reported yesterday - 12 in the community and one in isolation.
Director-general of health Dr Ashley Bloomfield said all 12 community cases are Auckland-based and none had travelled outside of the region.
All have a connection to the existing cluster.
It appeared the outbreak could be clearly linked to Americold in the first instance - and that this gave investigators the best lead. He said it may eventually prove to have no link, but an Americold worker had the earliest symptoms.
Three people are in hospital. One is in Middlemore. Two are in Auckland.
To date, 66 people linked to the cluster have been moved into quarantine.
New Zealand now has 1271 Covid-19 cases. Of the 49 cases in the community outbreak, all but three are linked.
There have been 1536 close contacts of the cluster identified by the contact tracing centre. All are self isolating.
Bloomfield said the response was "tremendous". He urged people who were called by the contact tracing team to take the call - or return it if they missed it.
Officials were working closely with two religious organisations to help with contract tracing.
Bloomfield said he wanted to thank people who were getting tested. He knows there are still some long waits.
"To those who are waiting very patiently, thank you very much."
Foodstuffs, which owns Pak'nSave has been contacted for comment.