MINEOLA, N.Y. (PIX11) — Military veterans will join a Long Island lawmaker Thursday to speak out against Rep. George Santos, in the wake of new allegations that the embattled Republican congressman took $3,000 from a fundraiser meant to help a veteran’s dying dog.

The veterans and Nassau County Legislator Joshua Lafazan, a Democrat, will condemn Santos in a 10 a.m. news conference, following the emergence of the latest allegations against the first-term representative of Queens and Long Island. A Thursday morning tweet sent from Santos’ campaign account called the allegation “shocking & insane.”

Military veteran Richard Osthoff, of New Jersey, told PIX11 News on Wednesday that he crossed paths with Santos in the spring of 2016, when his beloved dog, Sapphire, was in need of a $3,000 surgery to treat a tumor.

“The vet tech said, ‘Look, I know this guy Anthony Devolder who runs Friends of Pets United, and he’s a philanthropist and he helps people raise money for sick pets, dying pets, shelter animals,’” Osthoff said.

Anthony Devolder is one of the names used by Santos.

Osthoff said that Santos set up a GoFundMe drive that reached the $3,000 goal. But Santos then gave “excuse after excuse after excuse after excuse” to not hand over the money to Sapphire’s veterinarian, Osthoff alleges.

While Osthoff waited for the money, Sapphire’s tumor became inoperable, the veteran said.

“I had to panhandle for the money to get her euthanized and to have her cremated,” Osthoff said.

Michael Boll, of the New Jersey Veterans Network, said he called Santos and asked him to return the money to the donors.

“Anthony Devolder, aka George Santos, did not want to do anything like that and just basically disconnected the phone,” Boll said.

In a statement, a GoFundMe spokesperson said that the fundraiser in question was pulled from the site after the organizer failed to respond to a request for proof that the money had actually been delivered.

“When we received a report of an issue with this fundraiser in late 2016, our trust and safety team sought proof of the delivery of funds from the organizer. The organizer failed to respond, which led to the fundraiser being removed and the email associated with that account prohibited from further use on our platform,” the statement read. “GoFundMe has a zero tolerance policy for misuse of our platform and cooperates with law enforcement investigations of those accused of wrongdoing.”

A Thursday morning tweet from Santos’ campaign account called the allegation “shocking & insane.”

“The reports that I would let a dog die is shocking & insane,” the tweet read in part. “My work in animal advocacy was the labor of love & hard work.”

Santos has already faced a bipartisan slew of calls to resign over everything from admitted lies about his education and work history, to questions about his claim that his grandparents were Holocaust refugees, to an unresolved criminal fraud case in Brazil, in which Santos has denied wrongdoing.

He has repeatedly refused those calls to step down.