POLICE and drugs services have warned of a significant increase in the abuse of tranquilliser drugs which cost 50p a hit and are implicated in up to one-quarter of violent crimes in Scotland.

POLICE and drugs services have warned of a significant increase in the abuse of tranquilliser drugs which cost 50p a hit and are implicated in up to one-quarter of violent crimes in Scotland.

A survey by the Scottish Drugs Forum found that more than half of its treatment services raised concerns about the use of valium.

A study of offenders at Polmont by Bill McKinlay, governor of Barlinnie, and academics at Glasgow Caledonian University revealed eight out of 10 of those who used weapons had been under the influence of alcohol at the time, and one-quarter of them were on valium.

In some, the mixture of valium and alcohol provokes particularly violent behaviour.

Valium is one of a group of tranquilliser drugs known as benzodiazepines. They boomed in the 1960s as a supposedly safe alternative to barbiturates, but GPs subsequently reined back on prescribing them following evidence of significant side-effects including addiction.

Police have warned tens of thousands of illicit tablets are being imported from India and Pakistan. Illicit valium can be bought on the street for 50p a pill. Those obtained by prescription sell for £1.

Detective Sergeant Kenny Simpson, of the drug squad at Strathclyde Police, said: "Diazepam is a big issue, which may be increasing. We are seeing a lot more illicit blue tablets. Many of them are fake. We have always had concerns about the internet but if the servers are based abroad then we have difficulties in tackling them.

"It is a growing problem in relation to polydrug use. Cocaine and heroin users buy it to take the edge off and diazepam mixed with alcohol is very problematic."

David Liddell, director of SDF, said: "There has been a lot of concern over the years over polydrug use, which has led to less prescribing it to people with drug problems.

"However, demand for this type of drug has remained and people are able to access it through a variety of ways."