Police in Whangarei are trying to track down the people who damaged one of the town's historic buildings during an after-ball function.
Eight officers and an ambulance were called to the party at the Old Library just over a week ago.
The Whangarei Alcohol Harm Prevention Officer, Sergeant Howard Clement, said up to 50 young people were drinking around the venue late into the night, breaching a local liquor ban.
He said there was damage to the library, and several people were kicked out for drinking at the function.
Mr Clement said the police were still investigating who caused the damage and anyone with information should contact them.