POLICE have issued a warning to youngsters about a ‘legal high’ called Vertex, after a 14-year-old girl became ill after using the substance in Barnoldswick.

Officers will be attending an assembly at West Craven High School to warn pupils about the substance, which looks like cannabis and is marked as ‘not fit for human consumption’.

It is not clear how seriously the girl was affected, but officers said the illness was not life-threatening and she has made a full recovery.

The Barnoldswick incident happened on Saturday evening, and West Craven police said in a statement: “In this case the substance was called Vertex and clearly marked as ‘not fit for human consumption’.

“On the rear is a list of poisonous ingredients and a statement saying that the substance is a research chemical and is for lab reagent use only.

“The substance looks like herbal cannabis (green leaf material) and smells very sweet.

“On this occasion, thankfully the young girl has made a full recovery and the source of the substance has been dealt with.

“Assemblies have been arranged in the local high school to warn young people of the dangers should they decide to use similar substances.”

Legal highs can carry serious health risks, because the chemicals they contain have in most cases never been used in drugs for human consumption and are untested.

Sgt Kim De Curtis, of the West Craven Neighbourhood Police Team, said: "When people hear about legal highs, they think it's all right but just because a substance is legal doesn't make it right.

"Officers are going into the school to educate and warn the children about this stuff because it's so dangerous."

Anyone with information about ‘uncontrolled highs’ and who may be supplying them is encouraged to contact their local neighbourhood policing team by telephoning 101.