The Ashburton Community Alcohol and Drug Service (ACADS), which has held supervised after-ball parties for two Canterbury schools for 17 years, fears teens will now go rogue.
READ MORE: Canterbury after-balls pose prosecution risk
Organisers have pulled the pin on the parties, after Canterbury police warned they were going to crackdown on monitored events.
Police say anyone hosting an entry-fee after-ball is breaking the law, and could be prosecuted and hit with a $20,000 fine.
"We've always aimed for safe, supervised events," ACADS general manager Chris Clark told Paul Henry this morning.
She says months of planning goes into these events, and they have never had an incident at any of their parties.
"We work with the students and the parentsâ€¦ to make sure we do them in a safe manner and that the young people aren't at risk. That's why we started them."
Police wrote to Canterbury secondary school principals last week detailing the ruling making it illegal for anyone unlicensed to run a party where people drink and where there was any sort of money charged, regardless of age, this applies to organisers, bouncers and the partygoers themselves; meaning ACADS may face fines if its parties go ahead.