A spate of dog deaths around the Suffolk and Norfolk coasts are likely to have been caused by the animals eating shellfish contaminated with a toxin which is 1,000 times more potent than cyanide.

The Eastern Inshore Fisheries and Conservation Authority (IFCA) confirmed that the dogs have been killed by Paralytic Shellfish Poisoning (PSP).

It is caused by consuming shellfish contaminated with dinoflagellate algae, a deadly naturally occurring toxin.

The authority confirmed that the death of a seven-year-old Siberian Husky after eating a shore crab at Felixstowe Ferry in Suffolk earlier this month is likely to have been caused because of this poisoning.

Owner Chris Poole, from Kirton, said his dog died within 90 minutes of leaving the beach.

• Read more: Dog dies after eating crab on Felixstowe beach

Similar findings were also made in relation to a Golden Retriever that died having eaten a fish on the beach at Cley in North Norfolk on New Year’s Eve.

The Eastern IFCA said: “Testing last week on a variety of marine species, including brown/edible crab, spider crabs, shore crabs, velvet swimming crabs, dab and whelks from North Norfolk and Suffolk, have revealed low levels of PSP toxin in some of the samples and no PSP at detectable levels in others.

“PSP Toxins around the regulatory limit for bivalve molluscs were found in one sunstar starfish.”

It is thought that the contaminated shellfish was washed ashore due to winter storms, and have likely now been washed back into the sea.

Dr Andrew Turner, from the Centre for Environment, Fisheries and Aquaculture Science, said: “There is no risk to people or animals from the seawater. The only risk is from ingesting PSP-contaminated animals found on the beach, so simple precautions should be followed to ensure that pets and people do not eat anything they find on the beach.”

This may include keeping a closer eye on dogs on the beach, or muzzling those who may try to eat washed up fish.

Anglers who may also be fishing for Dab at this time of year have been advised to return their catches to the sea, after a small amount of PSP was found in one such fish in Cley.

Owners of pets that have become ill after consuming items on a beach are asked to report the matter to the district or borough council for the area where the incident occurred.