A New Zealand charity issued an urgent warning Wednesday about food parcels it distributed, saying it unwittingly included candy filled with a potentially lethal dose of methamphetamine, known commonly as meth.

Auckland City Mission, which works with homeless people, said the sweets were donated anonymously by a member of the public.

A food bank client reported "funny-tasting" candy, alerting the charity.

'Potentially lethal dose' of methamphetamine

The pineapple sweets wrapped in a bright yellow wrapper contained approximately three grams of meth, up to 300 times the level someone would usually take and could be lethal, according to the New Zealand Drug Foundation.

"Swallowing that much methamphetamine is extremely dangerous and could result in death," the foundation's spokesperson, Sarah Helm, said.

The charity said they had begun contacting up to 400 people to track down parcels that might have contained the candy. 

Helen Robinson from Auckland City Mission said that eight separate families had been affected so far, but no one had been hospitalized yet.

How have the authorities reacted?

New Zealand's police have opened a criminal investigation.

"An investigation is under way, and police are treating the matter as a priority given the risk to the public," they said in a statement. 

Robinson said the "revolting" taste meant most who ended up with the candies had immediately spat them out.

However, the charity's parcel recipients included clients of its addiction service. Therefore, news of the accidentally distributed meth caused significant distress.

"To say that we are devastated [is] an understatement," Robinson said.

rmt/lo (AFP, AP)