Five pots of potentially lethal poison have been stolen from an industrial unit.
The 100g pots of potassium cyanide were taken from a locked store cupboard at premises in Halesfield in Telford, Shropshire, on Tuesday night.
West Mercia Police warned that the deadly substance, which is used in the gold plating process, can kill in minutes if ingested.
A force spokeswoman urged anyone finding the containers to contact police immediately.
"The substance is in crystal form and looks similar to rock salt," she said. "Even as little as a teaspoonful could be lethal in minutes.
"The pots are described as around five inches tall and grey in colour with a white lid. They are clearly labelled Precious Metal.
Anyone with information is asked to call Telford Police on (08457) 444888.