Dunedin police have criticised a Speight's alcohol promotion, which offered free beer if students decorated their flats in the brand's colours and signs.
This comes after a car, painted in Speight's colours, was flipped on Thursday night in the middle of Castle St North.
Dunedin and Clutha area commander Inspector Dave Campbell said some of the behaviour by both the brewery and students was irresponsible.
"It is just not on, tipping cars over. That is just ludicrous.
"I have to question the breweries promoting alcohol to students - in fact, anyone promoting alcohol to students. It's not a great idea."
Dunedin Mayor Peter Chin said it was a "matter of concern" that such an alcohol promotion could happen.
Insp Campbell said police called in extra staff to Castle St on Thursday night because there "seemed to be a lot of extra partying".
In order to keep disorder to a minimum, patrons leaving the Gardens Tavern when it closed at 11pm were moved down Leith St North to avoid possible problems with partygoers in Castle St.
