Police will give advice and support to the Auckland school that last week kicked out 12 students for using and supplying cannabis.
A senior police officer is to attend tonight's Westlake Boys High School board of trustees meeting.
Headmaster Craig Monaghan said police were invited during a discussion yesterday.
Mr Monaghan said that "hand on heart", the problem had been stamped out and no additional cases of students involved with illegal drugs at school had emerged since publicity on the cases.
An in-depth investigation netted 16 pupils in a "small contained ring", after a tip off about a fortnight ago.
Twelve students were excluded - a punishment for behaviour judged to be "gross misconduct" for students aged under 16.
The other four were allowed to return to school under strict conditions.
North Shore Police commander Inspector Les Paterson said "youthful curiosity" was understood, but officers had a duty to investigate, educate and prevent.
"It appears the school has acted appropriately and with diligence in quickly getting onto this issue, and our experience is that Westlake Boys High is a very well managed operation."
New Ministry of Education figures given to the Herald yesterday showed that of the 169 exclusions throughout New Zealand schools for drugs and substance abuse, 51 were in the Auckland region.
In 2006, there were 1556 exclusion cases throughout New Zealand, of which 14 per cent related to misuse of drugs. The proportion of drugs related cases dropped from 24 per cent of exclusions in 2000.
Secondary Principals Association president Peter Gall said the drop did not necessarily relate to less use of drugs by students.
"I think it is more a result of different actions that schools take on that issue," said Mr Gall.
He said an example was a programme in the Far North in which a group of schools used drug testing and education from police and the local health board to tackle it.
Exclusion is similar to expulsion, but applies to students aged under 16, who must become enrolled in another school.