Police are appealing for information after a “significant” amount of suspected Class A drugs were found at a York spot popular with dog walkers.
The substance was discovered in the vicinity of the water treatment site in Osbaldwick on Thursday.
It was recovered by officers and tests are ongoing to confirm exactly what type of drugs are involved.
A North Yorkshire Police spokesman said: “This is an area that is popular with dog walkers, cyclists and runners. It is hoped local people may have information regarding any suspicious activity that could assist the police.”
Anyone with information is asked to call North Yorkshire Police on 101, or Crimestoppers on 0800 555111, quoting reference number 12160019766.