The longtime campaign treasurer and trusted aide of embattled Representative George Santos has resigned, according to letters she filed on Tuesday with the Federal Election Commission.
The resignation of the treasurer, Nancy Marks, places further scrutiny on Mr. Santos’s financial operations, which are the subject of several complaints filed with the F.E.C. and are being investigated by local, state and federal law enforcement.
It also leaves the Santos campaign in disarray, effectively rendering it unable to raise or spend money and placing it in seeming violation of F.E.C. rules.
Ms. Marks’s letters indicated that she resigned on Jan. 25 — the same day that the Santos campaign committee, as well as several affiliated financial committees, filed paperwork indicating that Ms. Marks was being replaced as treasurer by Thomas Datwyler.
But Mr. Datwyler, a veteran campaign finance consultant affiliated with a number of Republican committees, said that he told Mr. Santos’s team that he was not interested in assuming those duties. His lawyer, Derek Ross, sent a letter to the F.E.C. saying that Mr. Datwyler “did not file or authorize” the new campaign paperwork and that he did not authorize the forms “to be signed on his behalf.”
The lawyer also suggested the F.E.C. “refer this matter to the appropriate law enforcement agency to determine whether a crime has occurred.”
If someone filed paperwork on Mr. Datwyler’s behalf, that could be seen as a violation of federal law that prevents people from knowingly filing false information with the government, campaign finance experts have said.
It is not clear how Mr. Santos will proceed without a treasurer. In addition to ensuring that campaign finance reports are complete, accurate and timely, designated treasurers file reports, like the year-end filing that is due on Tuesday. And they help to ensure contributions do not exceed legal limits, an issue that the F.E.C. frequently raised with Mr. Santos’s campaign.
The lack of clarity over who, if anyone, is operating as Mr. Santos’s treasurer has already caused confusion. On Tuesday, a joint fund-raising committee associated with Mr. Santos filed paperwork to end its operations. Ms. Marks’s signature was on the paperwork, even though she had resigned as the committee’s treasurer the week before.
Ms. Marks did not immediately respond to a request for comment. A lawyer for Mr. Santos, Joseph Murray, said that “in light of the complaints filed with the F.E.C. it would be inappropriate” to respond.
Mr. Santos’s campaign spending has drawn raised eyebrows from election law experts. It included thousands of dollars in rent and a bizarre string of payments for $199.99 — one cent below the threshold at which F.E.C. rules require that candidates provide receipts.
This irregularity, among others, formed the basis of a complaint that the Campaign Legal Center filed with the F.E.C. earlier this month. That complaint accused Mr. Santos of using campaign funds for personal expenses and of perpetuating a straw donor scheme to obscure the source of $705,000 he lent to his campaign.
Another F.E.C. complaint was filed on Tuesday by the group End Citizens United about the roughly $260,000 Mr. Santos raised for a 2020 recount fund. Under New York State law, recounts are automatically initiated when the margin of victory is close. But Mr. Santos lost by 13 points, and the state does not allow for candidate-requested recount efforts, the complaint says.
In addition, the complaint — which names Mr. Santos and Ms. Marks — points out that a number of the expenses that the recount fund paid are identical to ones paid by the campaign, including a $2,026.25 laptop computer from Best Buy that appeared to have been purchased twice.
Mr. Santos has already showed signs of distancing himself from issues and discrepancies in his campaign finance filings.
After his campaign filed updated reports that raised new questions about the source of the $705,000, Mr. Santos told reporters in Washington last week that he had nothing to do with the issue.
“I don’t touch any of my F.E.C. stuff, so don’t be disingenuous and report that I did,” Mr. Santos said. “Every campaign hires fiduciaries.”