A killer virus threatens to wipe out a northern seal colony.

Hartlepool Council "strongly suspects'' that a sick seal found on a beach at Seaton Carew was a victim of phocine distemper virus (PDV).

Results of laboratory tests are still awaited, but the council says this could be the first indication that the local population is infected and there is now serious concern that the virus could run through the 70-strong Teesmouth colony.

PDV affects the immune system of seals, making them more susceptible to other illnesses such as pneumonia.

The RSPCA has over the last three weeks received 25 calls about seals on local beaches, resulting in seven collections or rescues. Three of those seals could have been carrying the disease says RSPCA Chief Inspector Neil Mitchell.

"There is quite a strong chance it (PDV) has arrived, but we wont know for definite until we get the test results back,'' said Mr Mitchell.

More than 1,500 dead seals have been reported around the UK's coastline since an outbreak of PDV began in the summer.

Mr Mitchell says the pattern formed during the 1988 international outbreak which wiped out half the European population of seals looks as though it is being repeated.

"Sometimes when we find these seals they are so weak, so sick they could not even take being transferred to the local vets,'' he said.

The diseased seal found at Seaton Carew had to be destroyed on the beach.

Dave Stubbs, head of environmental management with Hartlepool Council is urging people to stay off the beaches if they see a stranded seal.

He said: "We are asking people to be vigilant and report any sick or dead seals that they might come across. There is no need for anyone to panic or become unduly alarmed. "The virus poses no danger to people but we understand that it may be passed on to dogs as the canine distemper virus.''