Another person's wound up in hospital, after ingesting an unknown substance in Wairarapa

Police were called to a Masterton home last night, where a person was in a critical condition.

This follows three people being found unresponsive at a Tinui property on Saturday, after taking a powder they believed was cocaine.

Police say all four have recovered after receiving naloxone - a drug that reverses an opioid overdose.

They say the substances responsible for the harm are not believed to be the same, but they're investigating whether there are any links between the cases.