This comes after a student was arrested for urinating on a police car when officers cleared out the party in View St.
Senior Sergeant Anthony Bond, of Dunedin, said officers were called to reports of bottles being thrown at the party about 11pm yesterday.
When officers arrived, they discovered about 600 people inside and 200 in the street outside, Snr Sgt Bond said.
The amount of people packed into the building presented a safety hazard and police took a prevention approach, turning off the stereo and clearing out the party.
It took about an hour to remove partygoers.
A 20-year-old man was arrested for urinating on a police car and referred to the University of Otago proctor, Snr Sgt Bond said.
In an update this evening Snr Sgt Bond said officers spoke today to the occupants about the behaviour last night.
They would be referred to the Otago University Proctor, who also visited today. They were "reminded about host responsibilities involving noise, disorder and rubbish".
"Tomorrow the flat will be visited by Fenz and Dunedin City Council staff with police to remind them of their obligations in living there, as there is an occupancy limit, and the risks of overcrowding in an emergency."
Snr Sgt Bond encouraged students to organise their toilet stops as part of their planning for a night out, and not to expose themselves in public.
