"If symptoms develop, get a test and stay at home until you get a negative test result."
The party was advertised as Auckland's biggest New Year's Eve festival, running across three clubs in central Auckland as well as a "massive street party".
Venues included the AV Club, Saturdays and Side Door as well as a festival stage on Galway Street.
Acts included Koven, The Upbeats, State of Mind, Mt Eden Official, Body Ocean, and Weird Together as well as dozens of others.
More than 2000 people indicated an interest on Facebook prior to the event, with a post to social media late December reminding people that vaccine passes were required for entry.
The Ministry of Health's website did not specify a particular club or area visited by the positive case or cases. The Herald has asked the Ministry of Health for further information.
It follows the news that a Covid case was at the popular Auckland bar Longroom on New Year's Eve.
Anyone who visited the Ponsonby Rd nightclub after 10pm on New Year's Eve was told they must self-isolate for 10 days and get tested immediately as well as on day 5.
Staff at the club were considered casual-plus contacts and were only required to self-isolate for five days and return a negative test on day 5.