CONSERVATIONISTS say two dead seals washed ashore with bullet wounds to the head were almost certainly killed by fisherman.
The RSPCA received several calls from sickened members of the public who saw the dead mammals on a Hartlepool beach.
The bodies were last seen on August 23 but were reclaimed by the tide before anyone could properly examine them.
The discoveries were made as the phocine distemper virus (PDV) threatens to attack the region's seal population.
Five dead seals washed up on the Lincolnshire coast were found to have the disease, but no cases have so far been reported further up the North Sea coast.
Conservation experts say the butchered animals at Hartlepool were probably killed by fishermen who found them tangled in their nets. They are legally entitled to shoot the animals if they have a Home Office permit to own a shotgun.
Geoff Barber, of the Teesside-based Industry and Nature Conservation Association (Inca), said: "There is legislation for seals tangled in fishing nets that says they can be humanely killed.
"It is often almost impossible to get them out of the nets unharmed once they're tangled and some fishermen see it as a mercy killing.
"If those seals were caught in the same net, it is possible they were both shot and floated to shore at the same time."
A spokeswoman for the RSPCA said the killers would face a fine of up to £1,000 if they didn't have a permit.
She said: "If these seals were killed in cold blood, without reason, then that person is someone we need to find.
"This is a particularly sickening blow when you consider how many seals we could lose to PDV, which has been confirmed among UK seals for the first time in 14 years."
Hartlepool's seal population is made up of about 70 harbour seals and 30 grey seals.
Read more about the Animal Watch campaign here.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article