The breeder is an Amish dairy farmer in Lancaster County, Pennsylvania.
He alleges that back in 2017, Santos went to his home to buy puppies that he breeds as a side job.
"He says okay we are going to take that puppy and that puppy. And his assistant grabs the two puppies, takes them out the door, and he pulls out a check. I was like oh no, is this guy going to pay me with a check? By then I was very suspicious," the man who did not want to be identified said.
He says Santos' assistant put the dogs in a car and that Santos knew that the breeder only took cash, not checks.
Santos was charged with theft in Pennsylvania, but the charge was later dropped after he claimed that somebody stole his checkbook.
The breeder claims Santos wrote nine bad checks worth $15,000.
Meanwhile on Wednesday, residents rallied outside of Santos' office in Queens to demand that Congress takes action to expel him.
Members of Concerned Citizens of NY-03 are urging House Speaker Kevin McCarthy to bring a resolution to expel Santos to the House floor for a vote.
Demonstrators say Santos' lies about his background and heritage make him unfit to serve.
ALSO READ | The saga of Rep. George Santos: Inside his many fabrications, exaggerations, and embellishments
They say that if he won't resign, he should be removed so people in their district can get their needs met in Washington.
"You may have forgiven yourself but we have not and we will not," one protester said.
"At the end of the day, George Santos is nothing more than a pariah, he has no credibility with his GOP colleagues and no credibility with any representatives in the House," Jane Russell said. "So how is he going to fight for me and everything I need as his constituent."
In a tweet, Santos wrote, "Let me be very clear, I'm not leaving, I'm not hiding and I am NOT backing down."
He says he will continue to work for his district and added he looks forward to getting done what needs to be done.
ALSO READ | Man lunges at Buffalo supermarket gunman before he gets life sentence
Sentencing drama highlights lingering pain in Buffalo community
----------
* Get Eyewitness News Delivered
* More New York City news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube