Warnings of 'serious harm' after heroin discovered in powder sold as cocaine

Heroin has been found in a white power being sold as cocaine in the Auckland region.

A warning posted by drug information and safety website High Alert on Saturday said that "People who consume this powder thinking it's cocaine are at high risk of experiencing serious harm, including death."

The powder has been found only in Auckland so far and there is no information if it has been found in other regions.

"There is a concern this powder may continue being sold as cocaine," High Alert said.

"It is important to never assume that what drug you have is what it has been sold as."

The heroin was detected in a sample picked up by a clinic run by the Drug Foundation in Auckland today.

It comes just a week after New South Wales Health issued a public drug warning following multiple heroin overdoses after use of what people thought to be cocaine.

The Drug Foundation's chief executive Sarah Helm said the dose for heroin is smaller than the dose for cocaine, which means people could be taking what they believe to be a normal dose of cocaine, which could turn out to be a large dose of heroin.

Helm is urging people who think they have cocaine to get it tested.

"We're very hopeful that we're not gonna follow what has just happened in Australia in the past week and avoid mass hospitalisation or any fatalities."

In September, two people in Sydney died of heroin overdoses after using what they thought was Cocaine. Two others were hospitalised after overdosing.

Helm said she is not aware of the heroin sold as cocaine being found in other cities in New Zealand.

She said they will be closely monitoring the situation.

If someone takes a substance thought to be cocaine and experiences unusual effects, High Alert recommends they call 111 immediately.