Police investigating the deaths of two teenagers believed to have taken the legal drug mephedrone today issued further warnings after a man was arrested in a separate incident.
Humberside Police said a 27-year-old man was arrested at a nightclub in North East Lincolnshire yesterday after door staff searched him and found a quantity of what was thought to be mephedrone.
Officers with the force are also due to question three people in connection with the deaths of Louis Wainwright, 18, and Nick Smith, 19, who were found dead on Monday after a night out in Scunthorpe, North Lincs.
Today, police and partner organisations urged people to be careful of any substance marked as being for use with plants after warning that mephedrone - which is known under various names, including M-CAT and "miaow miaow" - is often sold on the internet as plant fertiliser.
A spokesman said: "It is sold as a plant food to get around fit for human consumption checks but should not be ingested.
"Due to the potential health risks posed, members of public are urged not to eat or drink any substance labelled for use with plants and we are asking parents be vigilant to ensure their children are not taking anything that could be potentially harmful to their health."
Kim MacDermid, young people's substance misuse service project manager for North East Lincolnshire Care Trust Plus, said: "Mephedrone and methadrone are short lasting stimulants, so users tend to binge on them.
"They can cause heart and circulatory problems due to increased blood pressure. It has been known to cause convulsions in some users and regular use will cause depressive, irritable comedowns. However, being relatively new, many health risks are not yet apparent."
Kay Aisthorpe, from the North Lincolnshire Safer Neighbourhoods Partnership, added: "We are aware this drug is known as a 'legal high' but the effects can be unpredictable as they contain a range of dangerous chemicals and you never quite know what you are taking when you take this substance.
"Just because this is legal to possess, it does not mean that this is at all safe and please be aware that most of these substances are illegal to sell, supply or advertise for human consumption, under medicines legislation, due to the effects they can have on the body.
"People who take M-CAT with other substances, for example amphetamines and alcohol, greatly increase the risk to themselves and potentially this could be fatal.
"Humberside Police is continuing to encourage anyone who knows somebody who has possession of the drug to either hand it in to a local police station or dispose of the substance as soon as possible and contact police.
"The families of Louis Wainwright and Nicholas Smith have suffered a tragic loss and do not want any other families to similarly suffer."
Two men, aged 26 and 20, and a 17-year-old boy are currently in custody at Scunthorpe Police Station waiting to be questioned in connection with the deaths of Mr Wainwright and Mr Smith.
A force spokesman said police were also trying to locate people who had supplied drugs in connection with this incident.
The man arrested on suspicion of the unrelated offence in North East Lincolnshire also remains in police custody while officers work to identify the substance found in his possession.