The Drug Foundation has called for urgent action from the Ministry of Health regarding synthetic cannabis and other drugs.

The Foundation said the Ministry should set up an early warning system for dangerous drugs, following the deaths of eight people linked to synthetic cannabis.

Executive director Ross Bell said there is already a Europe-wide early warning system that monitors what is happening with new drugs, and issues advice when dangerous drugs are found.

"I really would hope that the Government would show more urgency. This is a problem that isn't going to go away. There will always be new chemicals being cooked up, those chemicals are going to poison people and make people really unwell."

Almost 50 bags of synthetic cannabis were seized in a raid in Ranui last week.

Police are also aware of reports of a "bad batch" of synthetic cannabis, following the recent Auckland deaths that may be linked to synthetic cannabis use.

However, police have no scientific evidence at this stage to suggest that this is the case.

Bell said the public should be informed about the test results of dangerous drugs so they can know exactly what chemicals are in them.

"We have to ensure that whoever finds out what these chemicals are, whether it's police or accident and emergency staff, should share that information to other agencies and to the wider public."