Extra police from Christchurch, Central Otago and Invercargill are being brought into Dunedin for the arrival of an unofficial "Undie 500" student car rally on Friday night.
The event was cancelled after last year's weekend-long rally ended in rioting and 70 arrests.
But Inspector Dave Campbell is expecting a number of Canterbury University students to arrive in Dunedin on Friday night.
A temporary liquor ban is in force in the student quarter all weekend and the police will maintain a constant presence in the area.