Another suspected overdose in Wellington brings total to six, with one death

Another person has been hospitalised following a suspected GHB overdose in Wellington, bringing the total to six.

One person had died, a woman, at a Wellington castle-like mansion after drinking GHB from a bottle, her friend earlier told RNZ.

Detective Inspector Anna Grant said a new case was detected in Wainuiomata overnight.

That person was in a serious condition and still in hospital on Monday.

Grant said police were still investigating the matter as a priority given the risk to the public.

It included working to identify if the cases were connected and where the supply came from.

"Police strongly urge the public to take extreme caution around drugs of this type.

"While it's safest not to use drugs at all, New Zealand's drug early warning system High Alert recommends at the very least getting substances checked before taking them," Grant said.

Nearly half of GHB tested not what people think it is

The Drug Foundation warned that nearly half of GHB tested was not what a person thought it was.

Between January and March, 46 percent was not what the person expected, executive director Sarah Helm told RNZ.

Helm urged anyone intending to consume the drug to get it tested first.

She said the Drug Foundation had seen an uptake in the drug throughout New Zealand "for a wee while now".

The main concern was that it was very hard to tell which 'G' substance a person had, Helm added.

"They're very potent, very easy to overdose on," she said.

Helm also urged anyone intending to consume the drug to be very careful not to consume it with others, particularly alcohol and other depressants.

"It can slow your body down, and then your body can begin to shut down."