CRIMES involving party drug ketamine have trebled in the past five years, figures have revealed.

There has been an increase of more than 250% in incidents in Glasgow involving the horse tranquilliser.

Official statistics show ketamine - dubbed "Special K" - was mentioned in more than 85 reports compiled by police officers across the city.

More than 40% of those incidents resulted in a crime being recorded.

It comes amid fears Scotland's streets are being flooded with new drugs that are being sold as ecstasy.

As well as using dangerous so-called "legal highs", dealers can add other substances, including horse tranquillisers to products, in an attempt to increase profits.

Ketamine was originally designed as an anaesthetic and tranquilliser, often used on horses during veterinary surgery.

It was first banned as a recreational drug in 2006.

Last month, the UK Govern­ment announced it would upgrade ketamine from a Class C to a Class B banned substance.

It means jail terms for anyone caught in possession rise from two years to five.

Other Class B drugs include cannabis, amphetamines, such as speed, and barbiturates.

In 2009/10, there were just seven incidents in Glasgow involving ketamine.

Data released to the Evening Times show 25 incidents were recorded in the last 10 months.

A police spokeswoman said: "Ketamine is a drug, that creates similar effects as ecstasy, and is often associated with the dance scene.

"It is not a drug believed to be widely in circulation within Glasgow."

Figures show about 120,000 people across the UK took the drug last year. Some regular users were forced to have their bladders removed.

A Scottish Drugs Forum spokeswoman said: "Ketamine prevalence remains low in treatment services compared to other drug use in Scotland.

"It is much more widely used in the rest of the UK.

"The main concern for services would be the longer term risks resulting from habitual use, which has led to the recent reclassification, mainly the issues around bladder damage.

"Reports of ketamine use appears to be increasingly slightly in parts of Scotland, including the Glasgow area, according to anecdotal reports from services.

"It is unclear whether this is due to increased prevalence or if awareness of the drug has increased and therefore services are recording more accurately.

"It is rare for users to notice significant side-effects from use unless they are using regularly.

"So this, in part, may explain why there are relatively low levels of people presenting for treatment."