The World Health Organization (WHO) said that firms selling electronic cigarettes shouldn't portray them as aids to help people stop smoking the real things.

Dr Ala Alwan, assistant director general of the organizations Noncommunicable Diseases unit, said: "The electronic cigarette is not a proven nicotine replacement therapy. WHO has no scientific evidence to confirm the product's safety and efficacy. Its markets should immediately remove from their web sites... any suggestion that WHO considers it to be a safe and effective smoking cessation aid."

A number of countries allow sales of the electronic fag, which creates a fine mist and uses a battery to deliver the hit.  A typical cartridge is the equivalent of 25 cigarettes and costs about £1 a cartridge. A packet of 20 cigarettes in the UK can cost as much as £6.30 in the West End of London.

The cigarettes are marketed by a number of different companies. A nationwide smoking ban is to be imposed on India starting in early October, as we reported earlier this week. X