Student drinking issues in Dunedin are "complex" and can’t be solved by arrests and prosecutions, a local police officer says.

A person was seriously injured over the weekend after a large student party in Castle St - reportedly attended by more than 400 people.

The University of Otago said the injured person was not their student.

A doctor who treated the young person told RNZ they had critical head injuries, and that others also had to be treated for alcohol and drug-related harm.

The party comes less than a week after a coroner warned students about excessive alcohol consumption, following the death of a 20-year-old who choked on his own vomit at a Dunedin party in 2023.

Otago coastal area prevention manager for community and youth Senior Sergeant Iain Notman told RNZ’s Checkpoint programme on Tuesday that Dunedin was a "unique environment" with a concentrated area of students, and the issue was ever-evolving.

“We just have to take a wider approach to some things. 

"I think in the past, trying to arrest or prosecute our way out of some of these things, and create a bit of a nanny state also, isn't often the way either.

"It is a complex and ever-evolving problem for us, and one we’re always trying to get better at.”

Notman said police were focused on partnerships with the university, Campus Watch and the Dunedin City Council to provide the safest possible environment for young people.

Asked if that approach was working, he said young people will always be young people - and that youth drinking was not just a Dunedin issue, but a problem nationally and internationally.

Asked if Otago University needed a culture change, Notman said that was a question for the university.

The lack of monitored student bars in the university area was also a factor to think about, he believed.

"Back from my days at university, we had 11-odd student bars where people could be monitored with experts and managers and food on site, whereas we're now down to zero, for example, in our student quarter.

"And that's increased the purchasing and drinking behaviour from off-site establishments, supermarkets and the like - and pushed a lot of the drinking back into the flats.”

The University of Otago said in a statement that a significant amount of work took place throughout the year to help students socialise safely and responsibly.

A spokesperson said staff visited flats to talk about hosting parties safely, and encouraged students to use the "Good One Party Register".

It said it also worked closely with police and student body OUSA, as well as other community partners.

A 24/7 Campus Watch service was in place, the spokesperson said, but noted it did not have the same legal authority as police and emergency services.