Thirty-one dogs, including several puppies, have been rescued by police in Co Tyrone.
The action came during what police have described as a "proactive operation" in the Coalisland area on Thursday.
Two men were arrested on suspicion of fraud and have since been released on bail, a PSNI spokesman said.
Inspector Joanne Gibson said five properties were searched in relation to suspected fraud offences related to the sale of puppies.
"All of the animals have been seized by PSNI as part of our investigation," she said.
"Two men aged 43 and 42 years old were arrested on suspicion of fraud by false representation. Both men have subsequently been bailed pending further enquiries."
Inspector Gibson also urged the public to be cautious when buying puppies.
She said, "Buying puppies from illegal breeders can have devastating results.
"Often these puppies die a short time after purchase or end up with infectious diseases such as parvovirus which is expensive to treat and often fatal."
She continued, "They can also suffer behavioural issues relating to fear and anxiety due to poor or no socialisation. It can be tempting to buy a puppy in these circumstances and often purchasers recognise things are not quite right.
"It is normal to want to 'rescue' a puppy in these circumstances but people must remember they are fuelling and supporting what is a particularly lucrative criminal industry."
Inspector Gibson made a direct appeal to anyone who has purchased a puppy in the area over the last six months.
She said: “ If any of these animals have tragically passed away, we would ask owners to contact police to assist with our ongoing investigation."
“We would urge members of the local community to be alert and vigilant of any suspicious activity involving the sale of puppies. If you believe you have knowledge of an illegal breeding establishment in operation then please contact your local Council Dog Warden – for Mid Ulster District Council please ring 03000 132 132 and to report a welfare concern please contact 028 8225 6226 to speak to an Animal Welfare Officer.”