WALKING DEAD: Comatose '˜zombies' invade Chesterfield as psychoactive drugs grip town's addicts

The drugs, which go by the street names of ‘Mamba’ or ‘Spice’ - were criminalised last year - but remain as popular as ever.

Media reports from other parts of the country appear to show users turned into ‘zombies’, unable to speak or move.

Steve Holme, a former officer who is now Derbyshire Police’s expert on drug policy, said: “These drugs have become attractive to people who are homeless and rough sleepers - people who want to blot their lives out.

“They are not that widely used - heroin is a much bigger problem. But amongst a certain group of people they have become popular.

“A young lad in this area nearly died four or five years ago after taking this stuff.”

Steve says there are hundreds of these synthetic cannabinoids (SCRAs) being sold on the streets of Derbyshire at the moment.

However, as ‘Mamba’ has become the generic term in this area, he said users cannot know exactly what they are taking.

After a man was taken ill under the bus shelters on New Beetwell Street last week, several Derbyshire Times readers said they had seen people in an unresponsive state around Chesterfield town centre in recent days.

Katie Carlile said: “Just this Wednesday there was paramedics outside the probation centre.

“From what I saw it seemed like he’d taken something and wasn’t co-operating with paramedics. Think it’s that ‘spice’ drug.”

Because many of these substances are new the short and long term effects of taking them are unknown.

Most have never been tested on humans and are often marked ‘not for human consumption’.