A ban on nicotine in e-cigarette products is under fire from a visiting health professional who says it is naïve and doing more harm than good.

University of Queensland professor Wayne Hall is presenting at Thursday's e-cigarette symposium at the University of Auckland and will join leading experts in calling for the prohibition to be lifted.

Electronic nicotine refills are illegal to sell over the counter but can be legally bought from overseas suppliers for personal use.

Hall said the law created an "absurd situation" where people were resorting to the black market to buy products that contained a less harmful form of nicotine than normal tobacco cigarettes.

"You can buy cigarettes wherever you like but you're not allowed to buy something that's probably a great deal safer, at least in the short term," he said.

"It does seem a pretty silly policy."

He said the government needed to acknowledge the widespread use of the e-devices by reversing the ban and regulating the nicotine products to ensure their safety.

"There needs to be a middle ground where there is some form of regulation.

"Assuming that if we just ban it no-one will use it is a naïve position."

Ministry of Health enforcement officers have targeted stores selling nicotine e-cigarettes over the past six months and issued verbal warnings to several retailers.

Penalties for selling nicotine liquid or cartridges can be as high as $10,000 though no fines have been handed out yet over e-cigarette sales.

The ministry's senior tobacco control adviser Brendon Baker said the ministry was "stuck in the middle somewhat" between wanting to encourage people to quit smoking, but not having enough evidence to recommend e-cigarettes as a safe alternative.

University of Auckland associate professor Chris Bullen agreed there was more research needed but said the current law was "frankly bizarre".

"It's not a particularly logical or helpful policy," he said.

Bullen led a clinical trial on e-cigarettes that found the vapour emitted was less harmful than the toxins inhaled through smoking tobacco and that, if used with nicotine, can be just as effective as patches at helping people quit smoking.

"They're not a magic bullet, but it would be part of the solution in reducing smoking rates," he said.

The ban had only succeeded in driving sales online or to questionable retailers, he said.

"When you're driving it underground you get people selling all sorts of weird and wonderful things."

Stuff visited a range of dairies and specialty smoking stores on Auckland's Karangahape Rd and found most sold nicotine refills behind the counter.

Retailers claimed they were legally able to sell them, as long as the devices were not pre-loaded with nicotine.

Baker said it wasn't quite that simple and selling them separately "would not be a way around the law".

One of the country's biggest e-cigarette retailers, Cosmic, complied with the rules and did not stock nicotine products. Owner Mark Carswell said the popularity of e-devices had nevertheless exploded, with a 400 per cent rise in sales in the past six months.

Most users were smokers trying to quit, and were largely in the 30 to 60 age group, he said.

"For cutting down smoking the reality is they're f***ing effective."

Carswell said the position of New Zealand and Australia's governments in not approving nicotine sales was "stupid" and stood out as an anomaly when he visited trade shows for e-cigarettes around the world.

"It seems like science and the Ministry of Health are at odds."

Associate Health Minister Peseta Sam Lotu-Iiga said he was keen to hear more from health experts on the issue and would be attending Thursday's symposium.

BEHIND THE VAPE

What are E-cigarettes?

E-cigarettes are devices that come in the shape of a pen. They work by heating a solution containing nicotine and/or other chemicals, which are inhaled by the user, releasing an odourless vapour.

Are they legal?

Medsafe has not approved any e-cigarette for sale in New Zealand and it is, therefore, illegal to sell an e-cigarette that contains nicotine.

However, users can legally buy nicotine-based products online, if it is for personal use. And retailers across New Zealand still sell them under the counter, by selling the nicotine refills and the e-devices separately.

What are the Ministry of Health doing?

They are currently "considering whether current regulations are appropriate".

Source: Ministry of Health