Schoolgirl Gabrielle Price died last week after taking mephedrone, a freely available ‘legal high’ that dealers sell with impunity. Ben Leach reports

"It’s big business," says Sunny, a 35-year-old ex-con who runs one of the many websites that trade in mephedrone, a party drug and so called "legal high" that the Government is under pressure to ban.

"I run the website with two other people and we make around £25,000 a week. We get dozens of orders every day from people all over the country. We never dreamt that we could make so much money from it."

Sunny is one of many unscrupulous individuals who are profiting from the huge surge in the popularity of mephedrone, a white powder more commonly known as "meow meow".

The drug is cheap and gives a high similar to that of Ecstasy and amphetamines. It can be bought by anyone with access to the internet and a credit card.

Last week it sparked a wave of controversy after being linked to the death of schoolgirl Gabrielle Price. The 14-year-old suffered a cardiac arrest and died in hospital after taking a suspected cocktail of drugs including mephedrone.

Miss Price’s death is not the first harrowing account of the devastating effect the drug can have. Earlier this year, Durham Police warned about the dangers of mephedrone after one user ripped off his own scrotum while suffering hallucinations in which he believed centipedes were crawling over his body and biting him.

Indeed, the drug is the most popular of a new batch of legal highs that are engineered in Chinese laboratories before being shipped to Britain. Most have a range of side-effects that include convulsions, breathing problems, nosebleeds, depression and psychosis. Some even carry a risk of coma or death.

In March this year, Chris Dyer, a promising, 24-year-old university graduate from Peebles, in the Scottish Borders, died following an agonising five-year battle with addiction to one such drug, GBL.

"The disease of addiction means many things to me," he wrote in his diary 16 months before his death. "I live a life of unhappiness, lies and deceit. I devastate my family, but besides being there for me, there is little they can do. It will ultimately lead to my death, unless I stop."

But worryingly, Mr Dyer’s story is far from unique. This year GBL (Gamma-Butyrolactone) has also claimed the life of Stephanie Balcarras, 22, and Hester Stewart, 21. In April, Miss Stewart, an outstanding medical student at Sussex University, was found dead at a house in Brighton after taking the drug during a party. Last month, Miss Balcarras, from Hamilton, South Lanarkshire, was found dead at a friend’s house in Blackpool, having apparently taken the drug the previous night.

GBL is converted in the stomach into the notorious date-rape drug GHB, which was banned in 2003. Doctors first gave warning about GBL in 2005, when one said that it was "vastly more dangerous than Ecstasy". This month politicians finally passed legislation that will make the drug illegal. The ban will come into force just before Christmas.

Other "legal highs" will also be banned, including synthetic cannabinoids, which are sprayed on herbal smoking products, and chemicals such as BZP (Benzylpiperazine), part of the piperazine family of stimulants that are an alternative to amphetamine.