A secondary school is using a sniffer dog and testing agency to check students for drugs and alcohol at its annual school ball.
Students from ACG Parnell College in Auckland, who are believed to have consumed any drugs or alcohol, will not be allowed to leave the ball at Crowne Plaza Hotel and will be taken to a room where they can either admit consumption or undergo testing.
In a letter to ACG Parnell parents, acting principal Edmund Coup said the measures would be used to prevent issues involving alcohol, drugs and bad behaviour that occurred at other school balls at the same venue.
"Clearly, I am vitally concerned to ensure that our school ball takes place without serious incident (or minor incident if it comes to that) and it is important to the school that we focus on the safety of our pupils and visitors."
The letter did not state how many sniffer dogs would be at the July 1 ball or which agency would be carrying out the drug testing. The school did not respond to Herald requests for comment this week.
Guests who were not students of the school and were suspected of using drugs or alcohol would be asked to have a parent or caregiver collect them.
Students of the college would only be offered this option if they confessed - if not, testing would be carried out.
The letter said anything other than a clear test for consumption would result in the student being sent home.
Possession of drugs or alcohol would be regarded as serious as consumption. The outcome for a pupil who denied a substance in their possession is drugs or alcohol "will depend on the result of the test" of that substance.
Coup said in the letter that any student found to have taken or possessed drugs or alcohol would also be sent before ACG's Executive Disciplinary Committee and could face being expelled.
Any students who returned a clear test would receive an apology from the principal and be allowed into the venue.
Another letter sent to ACG Parnell students, with an attached ball ticket application form stated: "it is the responsibility of attendees to have read, understood (and comply with) the details outlined in the letter sent to parents".
Auckland barrister Gary Gotlieb said by completing and signing this form students are not giving fully informed consent to be tested for drugs or alcohol.
He said that by not explaining the exact processes or procedures that could be used to test students, ACG Parnell is not providing students with "a fully informed situation of what they intend to do".
"I think that needs to be spelled out."
Gotlieb also believed the letter should outline a students right to seek legal and/or other advice before signing.
Crowne Plaza Hotel general manager Tim Pollock said he was not aware of any issues involving alcohol, drugs or bad behavior at previous school balls held at the venue.
He said the hotel provided an external security company for school balls and met with the organisers from each school to understand their security expectations.
St Kentigern College employed sniffer dogs and security guards to check students for drugs at their school ball in 2011, following the death of King's College student David Gaynor. He fell from an overbridge after being sent home from the ball that year.
Forensic toxicology testing showed David had alcohol and drugs in his system.
Secondary Principals' Association president Michael Williams said he was not aware of any schools having used sniffer dogs at their ball, although knew a number of schools used breathalysers.
"As principals we do take our responsibility to keep the children safe very, very seriously and deterrents like [sniffer dogs] can be really useful to send the message out to remind students that we are serious...that it's a school event and we want to keep you safe."
A police spokeswoman said the matter was not for police to comment on.