• Embattled Republican Rep. George Santos has denied allegations that he took off with thousands of dollars he helped raise for a disabled veteran seeking a lifesaving surgery for his service dog.
• Santos, who was already facing bipartisan calls for his resignation, denied the reporting as "Fake" in a text to Semafor.
• Santos, after winning his congressional race, admitted to lying about key details of his background.

Embattled Republican Rep. George Santos has denied allegations that he took off with thousands of dollars he helped raise for a disabled veteran seeking a lifesaving surgery for his service dog.

Santos, who already faces bipartisan calls for his resignation, denied the reporting as "Fake" in a text to Semafor on Tuesday night.

"No clue who this is," the New York congressman added in a text to the outlet.

He appeared to be referring to Richard Osthoff, described by Patch.com as a U.S. Navy veteran who had been put in touch with Santos in 2016 while seeking treatment for Sapphire, his pitbull mix who had developed a stomach tumor.

Osthoff and another veteran told Patch.com that Santos, going by Anthony Devolder — a name Santos is known to have used in the past — set up a GoFundMe through his purported pet charity, Friends of Pets United. The New York Times reported last month that neither the Internal Revenue Service nor the attorney general's offices of New York and New Jersey could find any record of a registered charity by that name.

After the GoFundMe exceeded its $3,000 goal in June 2016, Osthoff said Santos directed him and his dog to a veterinarian in Queens, who said they couldn't operate on the tumor.

Santos then became elusive, the veteran said. Osthoff said Santos in a final phone call claimed he had moved the money from Sapphire's GoFundMe into his charity to use "for other dogs," because Osthoff "didn't do things my way," Patch.com reported.

Santos rebuffed Osthoff's request to let him use the money to take his dog to another vet, according to screenshots of text messages reported by Patch.

Sapphire died in January 2017, and Osthoff said he had to panhandle to pay for the dog's end-of-life services, according to the report.

Spokespeople for Santos did not immediately respond to CNBC's request for further comment.

The report from Patch marks the latest in a monthslong string of scandalous accusations against the freshman lawmaker, who after winning his congressional race admitted to lying about or embellishing key details of his background. He is facing local and federal investigations and has been the subject of multiple ethics complaints.

Santos was sworn in this month and has refused calls to give up his seat. He has apologized for "embellishing" his resume but said he committed no crimes.

Republicans in New York's Nassau County, where Santos' congressional district is located, have excoriated him and urged him to resign. But House Speaker Kevin McCarthy, R-Calif., has declined to join those calls, echoing Santos' own argument that voters of his district should be the ones to decide whether he stays in Congress.

On Tuesday, Santos was seated on two House committees.