This heartwarming photo of an adopted dog and his new owner grinning from ear to ear was meant to break the internet ... not land the cute pair in trouble and the dog under threat of being put down.

The picture of the photogenic canine, Diggy (previously known as Sir Wiggleton), and his human, Dan Tillery, went viral after the Detroit Dog Rescue posted it on Facebook on June 6.

However, police in Mr Tillery's hometown in New Jersey were forced to investigate after complaints were made about the dog, believed to be pit bull. The breed has been banned in the area for more than 25 years.

When police paid a visit to Mr Tillery and Diggy, they identified the dog as a pit bull. "Based on their observations, it was determined the dog was part pit bull/pit bull terrier," Police Chief Scott Underwood said.


Mr Tillery was told that if he doesn't get rid of Diggy by Monday, the smiling pup will be put down.

But the executive director of the Detroit Dog Rescue, Kristina Rinaldi, says it's a case of mistaken identity and that Diggy isn't a pit bull at all.

"Diggy is an American Bulldog and all of his paperwork says so," Ms Rinaldi told Detroit Free Press.

However, according to The Detroit News, the rescue group described the pup as a "pit bull mix" in a Facebook post on May 31 advertising his adoption. The post has since been removed.

Police have said that if Mr Tillery can obtain veterinary proof that the dog is not a pit ball, the matter will be resolved and Diggy can stay where he is.

"If he can show that it's not [a pit bull], then it'll be fine," Police Lt. Todd Hasselbach, told The Detroit News.

"He just has to keep those papers on him because his neighbours are gonna keep calling."