Six students were allegedly involved in a drug dealing incident where "horse valium" tablets were brought to school by one student, believed to be in year 10, and subsequently ingested by other students at school.

Kings Meadows High School principal Lee Barker said the six involved received disciplinary sanctions.

It is known that at least one of the teenage boys who took a tablet received a 10-day suspension.

Mrs Barker would not reveal what disciplinary action was taken against the student who brought the drugs to school.

A media police spokeswoman said police went to the school following the incident, and the matter was referred to the criminal branch for investigation.

"Upon being made aware of the incident, the school supported affected students and correctly followed the incident policy," Mrs Barker said.

"Drug use, possession or distribution is not tolerated in Tasmanian government schools with students taught about the harm caused by drugs, alcohol and tobacco.

"The school will continue to reinforce information about the dangers of substance misuse with students."

The Education Department's current drug management and drug education policy is under review.

It is stated under the current policy that the prosecution of student drug users or sellers is not the major objective of the police.

It also said principals have a responsibility to inform parents of any drug incidents, and police must involve parents if they interview young people who are under 18.