Middlemore Hospital dealt with six patients with Covid on Wednesday night, including two who turned up at the emergency department and later tested positive.
The patients at the emergency department arrived for non-Covid reasons and the infection was picked up as part of their assessment.
There were 45 new community cases in Auckland that day.
One of the emergency department cases was now in a Covid-19 isolation ward at Middlemore Hospital, the other discharged themselves and is being managed by the Auckland Regional Public Health Service (ARPHS).
"As is always the case at the hospital we will see quite a number of people with Covid," Middlemore Hospital chief medical officer Peter Watson said.
A total of six patients who turned out to have Covid-19 came in within a short period of time on Wednesday.
Watson said the patient who discharged themselves had not required in-patient treatment, but chose to leave before finishing the emergency department process.
There was initially some concern, but they were successfully followed up in the community on their return to their home address, he said.
"When you come into hospital you're not expecting to have Covid... This person I know had other people at home they were concerned about," Watson said.
"At this point we are very much still focused on ensuring we are across all new cases."
The person was being moved to a quarantine facility today, Director of Public Health Dr Caroline McElnay said.
Of the 34 patients in hospital who were considered close contacts, another six had been discharged and were being followed up in the community along with 32 outpatients already considered contacts, McElnay said.
The Ministry of Health has said risk to public health was deemed to be low.
Watson said Middlemore had had more Covid-19 patients than any other hospital and was well prepared.
There was a potential risk of exposure in an emergency department, but the risk was low.
None of the other positive cases at Middlemore in this outbreak had resulted in further infection, he said.