Up to 50 Northland teens flouted Whangarei's liquor bans at an after ball function in the city, with several arrested and five needing medical treatment for heavy intoxication.
The function was held at the Old Library in Whangarei on June 28.
Sergeant Howard Clement said between 40 and 50 young people were in the vicinity of the venue in the early hours of the morning, openly drinking alcohol in breach of the liquor ban.
"Many of these intoxicated people were trying to gain entry to the venue. Numerous incidents of minor disorder, intoxication and fights were dealt with by police," Mr Clement said.
"St John Ambulance staff also treated at least five heavily intoxicated young people, including one who was hospitalised."