A black panther has been blamed for mauling and killing sheep on a number of farms across Co Down.
Police and the USPCA have urged vigilance in Dromara following claims of sightings of a "big cat" terrorising livestock.
A PSNI spokeswoman said over recent weeks a number of farmers in the Hill Road, Ballynahinch Road and Mullaghdrin Road areas of Dromara and Hillsborough have reported sheep missing and others bloodied.
Some residents have also claimed to have seen a big cat in the same general area over a similar period of time.
PSNI statistics reveal that there were 23 reports of big cats stalking the countryside between February 2005 and April 2009.
Lisburn DUP councillor Luke Poots said sheep farmers were concerned for their livestock. "No one knows what sort of cat it is, but the marks left on the sheep are definitely from an animal," Mr Poots told the Belfast Telegraph.
"The farm believes that it is a black cat, like a panther.
"It is thought the animal came from the Mournes, through to Dromara and to Hillsborough."
David Wilson of the USPCA said that most large cat sightings come to nothing.
He said the only case where a cat was ever caught in Northern Ireland was on February 18, 1996 when police shot a Lynx at Garvallagh Road in Fintona, Co Tyrone.
"Report all suspected sightings to to the PSNI so that information can be collated, if there is something behind it police are the best people to tell," Mr Wilson said.
"A large cat isn't as likely as it would have been 10 years ago, when there was no dangerous wild animals legislation in Northern Ireland.
"I know of one positive sighting in Northern Ireland and that was a long time ago, it was a lynx up near Omagh, and it was shot by police."
Police are appealing for farmers who have lost sheep or other livestock in a similar way recently – or anyone who sees an animal which they believe to be dangerous – to get in contact with them immediately.
"Under no circumstances should any wild or undomesticated animal be approached," a PSNI spokesperson added.
It's not the first report of big cats in Co Down. In June 2009 a group of walkers reported seeing two large, wild cat-type animals in the area of the Bloody Bridge in Newcastle.
Both animals were described as being about the size of a Labrador, but with feline characteristics and black shiny coats.
Police can be contacted on 0845 600 8000.
There are many sightings of big cats across Northern Ireland each year. In September 2008, a lion was thought to be on the loose in Belfast. It was later found to be a dog. According to PSNI statistics, a "sandy mountain lion" was spotted on May 28, 2005 in Cookstown. But 2007 was the busiest year with eight different sightings, including a "large tawny cougar" in Armagh, a black panther in Lisburn and a puma in Foyle.