A substance believed to be rancid Palm oil has been found on both Cleveleys and Fleetwood beaches.
This substance has already been causing havoc in Cornwall where there are suspicions that it came onto beaches after being dumped at sea.
Dog owners are being warned to keep an eye on their dogs at all times as the substance is both fatal if ingested but also seems to be irresistible to them.
A dog owner from Fleetwood told 'Visit Fylde Coast': "Last summer I came across this substance on Fleetwood beach. It was a massive piece as big as a small armchair. There were other quite big pieces which floated. Me, the kids and my dog were all smashing it and the dog was playing with it.
If you do see any of this substance on Fylde Coast beaches, please report it to the appropriate local council as a matter of urgency.