The person is in a serious condition as police investigate whether the cases are linked.

Police are treating the matter as urgent 'given the risk to the public'.

GHB use is on the rise, and the Drug Foundation says small dose errors can be fatal.

A person died and four others were taken to hospital after suspected overdoses on Friday.

The person is in a serious condition as police investigate whether the cases are linked.

Six people have overdosed in Wellington since Friday, leaving one dead.