Toronto police are asking for the public's help in determining how a young Lhasa Apso puppy was found wrapped in a plastic bag, inside a trash bin in the Yonge Street and Finch Avenue area.

Police say the dog was found by a cleaner who heard whimpering from inside the trash bin behind an apartment complex at 23 Lorraine Dr., where the sounds seemed to be coming from a box.

Inside the box was a plastic bag containing the black and white puppy, which police believe is about four months old.

The cleaner gave the dog some water and promptly called police, who responded to the call at 7:40 a.m. on Thursday morning.

Const. Angela Rumney was the first officer on the scene.

"It was very surprising," she told reporters. "I'm a dog lover, so, of course, I went, and your first concern is for the puppy to make sure it's helped."

Police believe that the puppy may be a purebred dog and they intend to talk to dog breeders in an attempt to track down the person who abandoned him.

Anyone with information is asked to call police at 416-808-3200, or to call Crime Stoppers at 416-222-8477. They can also submit tips online at www.222tips.com, or text TOR and their message to CRIMES (274637).

With files from CTV's Jim Junkin