The ex-campaign treasurer for U.S. Rep. George Santos will plead guilty on Thursday to an unspecified felony in connection with the sprawling federal investigation of financial irregularities surrounding the indicted New York Republican, prosecutors said.

Nancy Marks, a veteran Long Island political operative, served as the campaign treasurer and close aide to Santos during his two congressional bids. Marks resigned amid growing questions about Santos’ campaign finances and revelations Santos had fabricated much of his life story.

Marks’ plea is scheduled to take place in a Central Islip courtroom on Thursday afternoon. It comes as Santos faces a 13-count federal indictment centered on charges of money laundering and lying to Congress in an earlier financial disclosure.

Marks and Santos haven’t returned messages seeking comment. A spokesperson for Santos, Gabrielle Lipsky, said his congressional office could not comment on the matter.

A spokesperson for the U.S. attorney’s office in Brooklyn declined to say what charge or charges Marks faced. She had not previously been charged, and Thursday would mark her first appearance in court.

The investigation of Santos, a first-term congressman, has also engulfed Marks, a key behind-the-scenes figure in Long Island Republican politics who built a business as a treasurer and consultant to dozens of local, state and federal candidates.

Marks has faced questions about the congressman’s unusual campaign filings, including a series of $199.99 expenses, just below the legal limit for disclosure. Santos, in turn, has sought to pin the blame for his unexplained finances on Marks, who he claims “went rogue” without his knowledge.

Any deal with prosecutors that requires Marks to testify in the case against Santos could be a severe blow to the Republican, who faces charges that he embezzled money from his campaign, lied in financial disclosures submitted to Congress and received unemployment funds when he wasn’t eligible.

While Santos has admitted fabricating key parts about his purported background as a wealthy, well-educated businessman, questions remain about what he did for work, as well as the true source of more than $700,000 he initially claimed to have loaned his campaign from his own personal fortune.

Santos has pleaded not guilty to charges he duped donors, stole from his campaign and lied to Congress about being a millionaire, all while cheating to collect unemployment benefits he didn’t deserve. He has defied calls to resign.

Besides Santos, Marks’ most high-profile client was former U.S. Rep. Lee Zeldin of New York, an ally of Donald Trump. She was Zeldin’s bookkeeper when he unsuccessfully ran for governor in 2022.

Marks, besides being responsible for keeping Santos’ campaign books and handling his regulatory filings, had unusual business ties to Santos, according to public records.

In 2021, she was listed as being a member of a political consulting firm incorporated in Florida, whose other members included Santos’ company and people who had formerly been affiliated with an investment company that had been shut down by the Securities and Exchange Commission over allegations that it was a Ponzi scheme.

When Santos was indicted, Marks wasn’t mentioned by name in court filings. But the indictment described an unnamed political consultant who it said had helped dupe donors who gave money that they thought was going to the campaign but was instead siphoned off for Santos’ personal use.

(AP)