Thousands of cases of "zombie-like" behaviour linked to synthetic cannabis have been reported internationally, but experts are not aware of any previous cluster of up to nine deaths in one city within a month.
"There have been very few deaths reported, so this thing suddenly happening in New Zealand is very different," Bell said.
He said the Auckland District Health Board and the Ministry of Health both asked him what was going on after the July 21 announcement, but he had no information.
He had asked police earlier that week to provide test results from Environmental Science and Research (ESR) on a big seizure of synthetic cannabis made in West Auckland in April, and was told an announcement was imminent.
"If the coroner and police knew earlier that week that they were going to put out a press release, they should have (1) provided the toxicology, because we know ESR had already seen that, and (2) there was enough time for them to line up at least the local DHB and probably also the Ministry of Health," he said.
Dunne, who was given one hour's notice of the release, said test results should have been made public.
"The sooner there could have been testing on what the substances were, the better position we would have been in to clarify what the specific risk is, and that would have helped clinicians," he said.
However Auckland City District Police Commander Superintendent Karyn Malthus said police were targeting drug suppliers whose cases had yet to be heard by the courts.
"In the past month, multiple search warrants have taken place across Auckland with a number of individuals arrested who are appearing before the courts."
She said police, district health boards, homeless shelters, the coroner and ESR were "working together to help progress prevention, intelligence, and enforcement priorities to respond to the harm caused by psychoactive substances such as synthetic cannabis and we will continue to do so".
ESR forensic chemistry manager Kevan Walsh said scientists were still analysing some of the samples of both synthetic cannabis and bodily tissues from the people who had died.
"Some of them we have completed. Some we haven't seen yet."
He said the cannabinoid substances in synthetic drugs were constantly changing, but about 60 per cent of samples seen in Auckland in the past six months were AMB-Fubinaca, which has been reported in other "zombie" outbreaks in the United States at up to 85 times the potency of natural cannabis.
A substance called 5F-ADB, "the other common one", was involved in the deaths of 10 people in Japan between September and December 2014.
Walsh said the compounds were manufactured mainly in China and South Asia, imported to NZ as powders, and then dissolved in alcohol solvents and sprayed on to herbal plant material - most commonly damiana, described online as an aphrodisiac tea.
Professor Michelle Glass, a cannabinoid expert in the Auckland Medical School, said natural cannabinoids were produced in the body to help control appetite, thought and other functions.
"You have lots of cannabinoid receptors in your brain. Only some are active right now," she said.
"When you take a drug, you are activating every one of those all at once. These are very potent compounds, they have effects at very low doses.
"That means if you don't have really careful control of the dosage, you can end up taking a very high dose, and I think that is what is happening here because it's just being sprayed on to the plant material and the dosage is not being closely controlled."
Known effects can include brain seizures, extreme anxiety, aggression, psychotic delusions, heartbeats jumping from the normal range of 60-100 beats a minute to 130 or, in one US case, 173 beats a minute, and in extreme cases cardiac arrest and kidney failure.
Community Alcohol and Drug Services (CADS) regional manager Robert Steenhuisen said the synthetic drugs were being used by three, mostly male, groups: socially marginalised people including the homeless; risk-taking teens; and naive adults who might accept a smoke at a party.
"They will seek an alternative reality, a new and alternative experience of daily living," he said.
"For people who really abuse it, they will use it as a way of managing their mental health symptoms. It reduces their symptoms or pressures, or people just want to switch off."
But in most cases treatment was possible.
"Yes, people make these mistakes, but they do recover," he said. "They can seek help and advice, and that helps the person getting back to recovery."
• CADS 09 845 1818; Alcohol Drug Helpline 0800 787 797.
What it does
Professor Michelle Glass, a cannabinoid expert in the Auckland Medical School, says natural cannabinoids are produced in the body to help control appetite, thought processes and other functions.
"When you take a drug, you are activating every one of those [cannabinoid receptors in the brain] all at once. That means if you don't have really careful control of the dosage, you can end up taking a very high dose, and I think that is what is happening [with synthetic cannabis] because [compounds] are just being sprayed on to the plant material."
Known effects can include brain seizures, extreme anxiety, aggression, psychotic delusions, heartbeats jumping from 60-100 beats a minute to 130bpm, and in extreme cases, cardiac arrest and kidney failure.
