Police in Plymouth say they have discovered a batch of cannabis which has been contaminated with glass.
It is the first regional instance of glass-contaminated drugs
The batch was seized in December 2006 and subsequent tests revealed it was contaminated with tiny glass particles.
They say it is the first instance of them finding so-called "grit weed" in Devon or Cornwall.
The health consequences are as yet unknown but officers warn one danger is that smokers could inhale glass into their lungs.
It is thought the glass is added to the drug to bulk up its weight before it is sold.