Initial results of tests carried out on the body of a seal washed up at Walton two weeks ago show it died of Phocine Distemper Virus (PDV).

The last epidemic of the disease in 1988 killed about half the seal population of northern Europe.

Robert Deville from the Zoological Society of London, who carried out the postmortem, said it was likely the disease would spread further.

Animals are treated at the Norfolk wildlife hospital

He told BBC Essex: "In the light of what's happening in the Wash area at the moment, we would expect perhaps more seals in the Essex area to die of distemper and spread around the rest of the coastline.

"But we'll have to wait to see what happens with that."

Since the disease hit UK shores in August, around one third of the seal population of Norfolk and Lincolnshire has died.

It has also killed animals throughout the waters of northern Europe.

There is no known cure for the virus, nor any way of preventing it.