Doctors in Canterbury believe a faulty batch of ecstasy has led to nine people being admitted to hospital in the last two days.
All of the patients were admitted to the emergency department of Christchurch Hospital last night and today.
They were suffering from symptoms and side-effects associated with having taken the illicit drug, ecstasy.
A spokeswoman for the Canterbury District Health Board said: "They arrived in an agitated state, with dangerously high blood pressure and an elevated high heart rate.''
The spokeswoman said that because the nine people had arrived at the hospital over a short period of time, it is thought that a faulty batch of the illicit drug may be responsible.