Dutch health and safety watchdog NVWA has fined seven Amsterdam-based companies for selling illegal e-cigarettes, the Parool reports.

Juul is an American brand e-cigarette which contains three times the permitted amount of nicotine, making it illegal in the Netherlands. Its popularity among teens is growing, however, and Juul has now appeared on the Dutch market as well, both online and in physical shops.

The fines range from €450 to €4,500 for repeated infringements. All seven sellers, whose names have not been published for privacy reasons, are based in Amsterdam because the product is popular among American tourists, the paper said.

Junior health minister Paul Blokhuis said the sale of the illegal product is ‘unacceptable’. ‘I think the trend among teens to try e-cigarettes or shisha pens is a worrying one. That is the reason why the national prevention plan contains measures to limit the use and visibility of e-cigarettes,’ he told the paper.

The Parool cites the owner of a tobacco shop in The Hague who said Juul is very easy to buy online, especially via a foreign sites.

The American owner of Juul, Altria (formerly Philip Morris Companies), is rumoured to want to introduce the product in Europe, the paper writes, but that means the amount of nicotine would have to be reduced to a maximum of 20mg per ml.