One person remains in Auckland Hospital after taking a suspected bad batch of drugs at a music festival on Friday night.
Four people were hospitalised after attending the Listen In festival at Mt Smart Stadium - three in a critical condition, while a fourth was in a serious condition.
A St John spokesperson said they became ill after ingesting something at the event, but paramedics are unsure what it was.
It's reintroduced the idea of having testing tents, which tell you what substance you're taking, at New Zealand festivals.
The idea behind recreational drug testing, which has been endorsed by Police Minister Stuart Nash, is not to stop drug use but reduce harm, by letting consumers of illicit pills know if the drugs they are taking have been mixed with other dangerous chemicals.
Do you support testing of drugs at festivals?
Vote in The AM Show poll below.
Having trouble viewing the poll? Click here.