Beach warning after dog poisoned
24 October 2013 Last updated at 11:48 BST
Surfers and swimmers have been warned to avoid some west Cornwall beaches after a mystery substance was found.
A dog that ate the white glutinous substance died and several others were made sick, according to vets.
Public Health England said the substance, which is being analysed by the Maritime and Coastguard Agency, was a "source of worry".
Cornwall Council is putting up warning signs at beaches in the affected areas.
David George reports