Police have identified those pictured in a video showing a dog being kicked and dragged across the ground in Co Down.
The graphic video of an incident in Banbridge was uploaded to YouTube a week ago and shared on social networking site Facebook.
It shows the black and white Collie-type dog cowering in fear as what appears to be a male kicks it three times before lifting it by the scruff of its neck and carrying it away.
The other person in the video appears to be a woman who looks on as the dog is abused.
Animal charity the USPCA had offered a financial reward for information that leads to the conviction of those involved and police confirmed they are investigating the incident.
USPCA spokesman David Wilson said it is the worst footage featuring animal cruelty that he has seen on Facebook to date.
“The footage reported to us by many concerned Facebook users is utterly appalling. Those involved in the abuse must be placed before a court.
“The dog clearly needs veterinary care and we will provide this through our Newry Veterinary Hospital.”
One of the most concerning aspects is that the footage was uploaded to Facebook rather than being reported the police straight away, Mr Wilson added.
“The ease with which these things are being shared on social networking sites is a big concern.”
A PSNI spokesman said: “Police can confirm that they have received a report of footage of animal cruelty in the Banbridge area appearing on a social media site. Investigations are ongoing at this time.”
On Tuesday afternoon loca police confirmed those involved had been identified and said “a full investigation will be carried out”.
The video on YouTube had been viewed more than 6,000 times by yesterday evening, since being uploaded on December 29.
A number of people expressed their shock at the video’s contents, calling for it to be removed and urging whoever uploaded it to pass their information to the police.