A lack of staff and a series of technical problems plagued Healthline on Tuesday night, meaning about 60 people had to wait more than six hours on the phone, a review has found.
Aucklander Lisa-Marie told RNZ's Checkpoint she had to wait almost eight hours on the phone to Healthline on Tuesday night.
On Saturday, she visited Kmart in Botany, a location of interest, while a person infected with COVID-19 was on shift. It was announced on Tuesday that Case J, a community case linked to Auckland's existing cluster, had gone to work on Friday and Saturday before testing positive.
Lisa-Marie's call was not answered until about 5:40am the next day - and her phone showed a call time of seven hours, 44 minutes.
Her experience elicited an apology last night from Associate Health Minister Ayesha Verrall, who said the delay was not acceptable and would be followed up on.
Now, after a review ordered by the minister, the Ministry of Health has told RNZ that although 36 people were rostered to work, it is not clear if they were all on shift - and there were just five staff in the Auckland contact centre.
They were dealing with huge call volumes, the Health Ministry said. Following the announcement of a new community case linked to Papatoetoe High School, call volumes spiked - the average wait time jumping from under a minute to 36 minutes.
Healthline answered 3744 calls on Wednesday - most of which came between 7am and 11am and had an average wait time of 56 minutes.
The ministry said Healthline has since increased the number of rostered staff by eight times - and wait times are now mainly under 20 minutes.
The review also found a series of technical issues.
One problem resulted in 60 people's calls being incorrectly prioritised, meaning they had to remain on hold for more than six hours. The ministry said that was likely to have happened to Lisa-Marie.
The ministry said this problem was "being addressed".
Another problem caused 92 people between lunchtime on Tuesday and midnight on Thursday to be cut off after waiting on the phone for two hours. This affected people who were on hold, or even mid-conversation.
It is not clear what that issue was exactly, but it is said to have been resolved.
The ministry said they would like to apologise to everyone affected, and said people should continue to call Healthline for information about COVID-19.