American e-cigarettes which have been banned in the European Union for their high nicotine content have been found on sale in Amsterdam.

The liquid used in Juul cigarettes contains nearly three times the maximum permitted level of nicotine – 59 ml against an EU limit of 20ml – making them highly addictive, according to the public health agency RIVM.

‘The use of nicotine salts in Juul is concerning,’ Reinskie Talhout, tabacco specialist at the RIVM told the Volkskrant. ‘They make it easier to inhale the vapours from e-cigarettes and make the product highly attractive to beginners. We need to keep a close eye on this product.’

The newspaper said it found seven shops in Amsterdam that were selling the e-cigarettes illegally in a two-hour tour of the city. One owner who imported Juul products directly from the US said they accounted for 25% of his turnover. ‘Every day there are more customers for it,’ he said.

Juul has a 70 per cent market share in the US and is popular with young people there. The company is reportedly developing a lower-nicotine version that meets EU standards so that it can enter the European market.

A spokesman told the Volkskrant it would investigate illegal sales of its products in Dutch outlets. ‘We wish to emphasise that all Juul products in the market in the Netherlands now are unauthorised,’ he said.

The spokesman added that the company was ‘doing everything to keep the product out of the hands of minors.’