Electronic cigarettes could lead to smoking being normalised once again, public health minister Michael Matheson has warned.
Mr Matheson restated the Scottish Government's commitment and support for the regulation of the devices as he questioned the motives of tobacco firms.
E-cigarettes will be licensed as a medicine in the UK from 2016 under regulations to be introduced by the Medicines and Healthcare Products Regulation Agency.
The devices, which deliver nicotine vapour instead of tobacco smoke, are often marketed as a less harmful alternative to traditional cigarettes.
But Mr Matheson has warned that they may increase the appeal of smoking among young people.
Mr Matheson said: "E-cigarettes may potentially help many people smoke fewer cigarettes, or even stop altogether.
"While e-cigarettes aren't proven to be safe, current evidence suggests they are almost certain to be less harmful than tobacco.
"On the other hand, the devices could also re-normalise smoking.
"They are addictive because they contain nicotine and promotional activity may increase their appeal to young people.
"The tobacco industry is heavily investing in e-cigarette companies. I am suspicious of this.
"There is too much history to believe claims that such diversification is motivated by newfound philanthropy or a true belief in harm reduction.
"The case for restricting the sale of e-cigarettes to young people makes sense. Again we need to work through the practicalities before bringing forward specific plans."
Mr Matheson also restated the Scottish Government's commitment to introduce plain packaging for cigarettes and to legislate on this independently if the UK Government does not introduce the measure.