Druggies now have a new legal high to get off their heads with – phenazepam, a potentially lethal epilepsy pill.

Wasters are using the drug after the previous legal drug of choice, meow meow, was banned in 2010.

Phenazepam, widely available on the internet, apparently produces the effects of the former "legal high", but with a higher risk to a user's halth.

Britain's top toxicologists yesterdaywarned people to tread carefully with phenazepam after the drug was linked to a string of overdose cases.

It was found in the blood of nine people who died in Scotland, although seven of them had also taken opiates.

Phenazepam is used to dampen symptoms of epilepsy and anxiety and can be legally obtained here online under the name Bonsai Supersleep – a mixture of phenazepam and other drugs also used as a substitute for tranquillisers like valium.

Dr Peter Maskell, of the University of Dundee, warned in the British Medical Journal: "Phenazepam use in the UK is on the rise. It can be obtained legally on the internet and is being used as a replacement for other drugs.

"Doctors should be aware of both the availability and use of phenazepam in the UK."