Despite health officials working closely with tobacco retailers, two under age volunteers have been sold the product in a recent operation.
The controlled purchase operation was conducted by MidCentral Health smokefree enforcement officers who caught two retailers selling cigarettes to an underage volunteer.
There has been a total of four sales this year, compared to just one in the same period last year.
Smoke-free enforcement officer Neil Adams says it was disappointing to see the sales had increased.
Health officials supply retailers with information on how to comply with the Smoke-free Environments Act which forbids selling to anyone under the age of 18.