Potentially-hazardous chemicals washed up on beaches had to be dealt with by firefighters wearing protective clothing earlier this week.
Members of the public are now being warned to contact the police or coastguards with any sightings of the clear polythene bags containing a further green bag of chemicals.
The bags were washed up on beaches in the Fowey and Polridmouth areas.
It is understood the kits are for military use and are designed to detect poisonous gases. They contain sealed bottles of mercury cyanide and sodium hydroxide and have a Nato serial number on them.