A West Auckland medical centre has been temporarily closed after a patient tested positive for Covid-19 during the weekend.

White Cross staff who were working when the man visited the New Lynn clinic on Saturday night are now being tested and the clinic is closed for a deep clean.

Tāmaki Health CEO Steffan Crausaz said the man was wearing PPE during his visit which took place sometime between 6-7pm.

"Like all patients, he was issued with a mask before entering the clinic and wore it the entire time he was in the clinic," Crausaz said.

"All staff who were working at the clinic when the Covid-19 positive patient attended are being swabbed and will remain in isolation if required, in accordance with the standard Ministry of Health protocols."

Crausaz said other patients at the clinic at the same time are now being traced as part of standard procedure.

"As an extra precaution, we ask that anybody with symptoms of Covid-19 phone their family doctor's clinic before they attend," he said.

Two other medical centres were shut for 48 hours last week after they were both visited by Covid positive patients.

Glen Eden's Westview Medical Centre and Ōtāhuhu Health Centre were closed for deep cleaning.

Those two positive cases were among the four already announced by the Ministry of Health on Tuesday night.

A former prime minister of the Cook Islands - who is also a prominent doctor in the Auckland community - was identified as the Covid-19 patient in hospital at the weekend.

Dr Joseph WIlliams, 82, is a well-know doctor within the Pacific community; particularly Cook Islanders.

While it was not yet known if he had come into contact with someone from the initial family of four who tested positive to the virus earlier last week, his medical practice was near the Americold cool store where a 50-year-old man from that South Auckland family works.

Thirteen new cases of were reported today - 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.