The free puppy has to be given back to the breeder when it reaches sexual maturity (around 7 months of age) so it can mate with another dog.
Leicestershire's RSPCA is warning that Modern Day Puppy Farming is happening in the East Midlands.
Modern-day puppy farming stops breeders from being limited to how many dogs they are breeding at once and helps them evade detection from the authorities.
RSPCA Woodside Branch, has received an increase in people who have taken in a puppy which was advertised for free.
This free puppy however has to be given back to the breeder when it reaches sexual maturity (around 7 months of age) so it can mate with another dog.
Mandy Morris, Customer Services Manager at the RSPCA Woodside Branch, said: "This puppy will always remain the breeder’s property unless they become sick, or unable to breed anymore, in which case the breeder will become uncontactable, and the individual caring for the dog will need to cover all costs. This is modern-day puppy farming. It usually funds criminal activities.”
Listen to Natalie Martin from RSPCA Woodside Branch here