RETAILERS who have sold certain 'legal highs' could face up to 10 years in prison following the initiation of prosecutions by the Irish Medicines Board (IMB) against several companies for the "unauthorised" sale and importation of medicinal substances.

In May, health minister Mary Harney introduced misuse of drugs legislation banning a wide range of psychoactive products being sold in so-called head shops.

As a result, the number of head shops in Ireland more than halved, almost overnight, from just over 100 to around 40. Most shop owners immediately closed because they did not want to risk prosecution for selling the substances.

It has now emerged that the IMB has initiated legal proceedings against four companies and one individual in relation to breaches of medicinal products regulations.

It is not known which products the companies were selling. However, the Department of Health has said an IMB investigation has found products such as Whack, Sextasy, White Ice, Amplified, Pure NRG and Snowblow at certain head shops.

Some of these products contain anaesthetics such as Lidocaine, the sale of which requires a licence. According to the IMB, the sale of other anaesthetics contained in these products, such as Dimethocaine, is "unauthorised" under Irish law.

None of these substances was covered in the blanket ban on legal highs introduced by the government in May.

A spokeswoman for the IMB said it had initiated legal proceedings over "breaches of medicinal products regulations" against Harmony Products Ltd, Simple Imports Ireland Ltd, Abacus Security Systems and Retail Products Ltd and against one James Bellamy. Bellamy could not be contacted for comment last week.

Anyone found guilty of the unauthorised sale of medicinal products covered under the Irish Medicines Board Act 1995 could face up to 10 years in prison and a fine of up to €120,000.