Dunedin police have slammed those who organised and attended a large party in the city's student quarter, with Covid-19 cases now confirmed in the community.
Officers shut down the party, which involved more than 300 people, just before midnight.
It comes as a series of student parties from Saturday to Tuesday are now considered close contact locations of interest.
Another planned in Castle Street last night was cancelled - a move police lauded.
"The party scheduled at a Castle Street address was cancelled earlier in the day by the flat occupants, which was a good move and the right thing to do in the circumstances. Police would like to thank them for doing this," Senior Sergeant Anthony Bond said.
But in nearby London Street, more than 300 people were found in the back yard of a flat last night.
"No QR codes present for people to scan, nobody counting the number of people present or checking/scanning vaccine passes, no security," Bond said.
"The nine flatmates at the address were difficult to deal with, claiming they did not know what their responsibilities were, all denying any wrong doing until eventually admitting that they had done everything wrong and the party got out of control.
"This is just blatant stupidity on the hosts' behalf to have a party like this and exceed the limits with the recent locations of interest being in the student area. Police will be returning today to speak with all occupants when they are sober and continue their investigation into how this occurred and who will be held responsible."
Soon afterwards officers attended another gathering at a nearby Pitt Street flat where about 50 people were in a small garage and on the street.
"Again, no QR codes, nobody scanning vaccine passes, poor attitudes from occupants," Bond said.
"Again police will return to speak to the occupants when they are sober and continue their investigation into how this occurred and who will be held responsible."
Both sets of flatmates had also been referred to the University of Otago's Proctor.