A hunt is on for an alleged dog snatcher who broke into a family home and stuffed a Chihuahua puppy into her rucksack before fleeing the scene.

Jolene Cooper, 14, single-handedly chased off the woman from her grandmother's house in Buckingham on September 1.

Footage from grandmother-of-22 Jo Cooper's security cameras shows a woman, dressed all in black, entering the property through the front gate while carrying a black backpack.

The 53-year-old had tasked her granddaughter Jolene to advertise and sell the six-puppy Chihuahua litter online.

CCTV footage shows how the woman opened Ms Cooper's front gate and brazenly entered the house.