The Obscure G.O.P. Bookkeeper at the Center of the George Santos Mess

The Zeldin campaign reviewed its filings in response to a request from The Times and found no issues, the former campaign manager, Eric Amidon, said. He added that he believed the F.E.C. to be mistaken about the contributions, but said that they would be refunded out of an abundance of caution.

The degree to which Ms. Marks was aware of Mr. Santos’s numerous biographical deceptions is not clear. But Florida corporate records show she went into business with him and some of his colleagues from Harbor City Capitol, a Florida-based investment company, just weeks after the Securities and Exchange Commission had shut the company down over concerns it operated as a Ponzi scheme.

In May 2021, Red Strategies USA was born.

Like Ms. Marks’s Campaigns Unlimited, the venture promised candidates convenience: one place to produce and place ads, manage social media and provide general political consulting.

Jordan Hafizi, a first-time candidate, turned to Red Strategies for help on a 2021 City Council race, paying the firm $22,450 to produce and promote a campaign video on social media, according to public campaign filings and a contract agreement reviewed by The Times.

But a review of the repository of ads on Meta, the company that owns Facebook, as well as a review by the ad tracking firm AdImpact, shows that only four Facebook ads were purchased on Mr. Hafizi’s behalf, and those were removed because they did not include a required disclaimer. The placements cost $3,800, though Mr. Hafizi paid Red Strategies $12,000, according to a person with direct knowledge of the arrangement.

Red Strategies was not the only company Mr. Hafizi patronized that was tied to Ms. Marks, who was also his treasurer. All told, Mr. Hafizi, who failed to garner the nomination in his City Council race, spent nearly $50,000 with Ms. Marks’s companies — roughly 60 percent of his campaign’s total spending, New York City campaign finance records show. He declined to comment.

As for Red Strategies, the company barely got off the ground: It handled just a few accounts, and was dissolved by the State of Florida in September 2022 for failing to file an annual report. By then, Ms. Marks and Mr. Santos were just a few weeks from an unlikely upset victory that would alter the course of their careers.

Rebecca Davis O’Brien contributed reporting. Sean Piccoli contributed research.