The number of so-called head shops has more than halved since the Government`s clampdown on previously legal highs, it was revealed today.

Justice Minister Dermot Ahern said there were 102 of the high street outlets around the country in May but only 44 one month after strict laws and harsh penalties for selling psychoactive substances were unveiled.

Garda drugs squad officers reported most of the head shops shut their doors after several products which mimic the effects of cocaine, Ecstasy and cannabis were outlawed two months ago.

But officers warned about 36 stores reopened within days, selling potentially lethal substances under different names.

Mr Ahern warned: "No matter what expertise is available, the imposition of controls on specified psychoactive substances will always be left playing catch-up with the creative capacity of the head shop industry to constantly develop new products."

But he added: "Head shop traders should be under no illusion. Those who thought they were safe to peddle newly marketed substances may also find themselves in due course defending their position before the criminal courts."

A ban on certain named highs was passed in May and a second raft of legislation to stop the legal trade in psychoactive drugs is due to go through the Dail next week.

"It is robust, innovative and urgent. In it I am providing that it will be an offence to sell, import or export unregulated psychoactive substances for human consumption," Mr Ahern said.

The legislation is similar to controls used in food safety regulations. Gardai and the courts will have the power to issue prohibition and closure orders on a shop owner or premises where psychoactive substances are being sold despite warnings to stop.

Anyone convicted of selling psychoactive drugs could face up to five years in prison.

The Garda National Drugs Unit has been monitoring the number of head shops around the country since the first restrictions were introduced in May. Mr Ahern said surveillance of the shops would continue.

PA Media