A senior Northland police officer is shocked three employees of off-licence premises sold alcohol to underage teens, including a manager "who should have known better".
The controlled purchase operation by New Zealand Police and Northland District Health Board had two 17-year-olds attempt to buy alcohol from 19 off-licensed premises in Whangarei on Valentine's Day.
There were three sales to the teens, the same as the total number of sales from four previous operations.
Whangarei police alcohol harm reduction officer, Sergeant Howard Clement, said they were almost back to square one.
"We thought things were really good," Mr Clement said. "It was a shock to us that it was not the case."
One of the employees who sold to the teens was a manager who should have known better, he said. "That's why they have a manager's certificate."
Police would be discussing the matter with off-licences this week, with further action likely.
Applications for suspension or cancellation of licence and manager's certificates would likely be made with Alcohol Regulatory and Licensing Authority (ARLA) for those premises who failed.
It was also possible the two employees who sold the alcohol could face a charge of supplying alcohol to a minor.
Police would not name the premises involved but said once the matters had gone through ARLA it was likely the names would be made public.
"The premises involved should have had better systems in place regarding the sale of alcohol to minors," Mr Clement said. "This operation highlights how easily our youth are able to access alcohol from licensed premises in Whangarei."
All off-licence premises and staff have to ask for photo identification of anyone that looks 25 or under, he said.
Northland DHB and police had been running joint Controlled Purchase Operations in Northland for almost 10 years.
A similar operation in February last year had one sale from 14 attempts, while another in June had two sales out of 17 attempts. Two further operations in August and September resulted in no sales, despite 31 attempts.
Manaia Primary Health Organisation health promotion manager Ngaire Rae said the results were disappointing.
"We know one of the ways we reduce alcohol harm is to control the supply of alcohol and retailers have a responsibility."