Police have arrested a man in Bristol whose car was found to contain 50 kilos of mephedrone.

The 41 year-old was stopped near Cribbs Causeway on the evening of the 24^th November while driving a silver BMW. Avon and Somerset Police say the man is currently in custody, and is said to be helping with their enquiries.

The drugs were arranged into 50 packages weighing 1kg each. The approximate street value of this amount could have been as much as £1.25 million.

Acting Detective Inspector Tina Harland said: ‘This operation reinforces our commitment to taking illegal drugs and those who supply them off our streets. It also shows the importance of the community working with us to beat this type of crime. Every piece of intelligence received is taken seriously and acted upon.’

Mephedrone is a Class B substance whose effects are similar to those of MDMA (‘ecstasy’). Known commonly as ‘Drone’ or ‘M-Cat’, it was prohibited last year under the Misuse of Drugs Act 1971 and its possession, importation and distribution are all now illegal.

The drug achieved relative popularity in the UK after being sold legally in shops and online as ‘plant food’. Estimates classed it as the fourth most popular illegal drug in Britain, behind cocaine, marijuana and MDMA. This popularity was attributed to its price: at one stage it could be bought for as little as £10 a gram.

Avon and Somerset Police called for the drug to be banned in 2010, following its widespread use in Bristol. In the same year it was linked to a death in the city. At the time the Bristol Drugs Project warned against the health risks of the drug, particularly when mixed with alcohol or other substances.

Paul Bunt, Avon and Somerset’s drug strategy manager, said that the seizure proved there was ‘still demand’ for the drug. He also warned against the dangers of similar substances: ‘There are also a range of very similar products being sold under the guise of legal highs. These are not legal and can cause hallucinations, blood circulation problems, rashes, anxiety and paranoia.

‘But one of the most dangerous things with mephedrone is that we don’t know many of the long-term effects.’