The former campaign treasurer for New York Rep. George Santos will plead guilty to at least one federal felony charge in connection with the case against the Republican congressman, according to court documents.

Nancy Marks, a veteran GOP operative, oversaw the Santos campaign's finances before being dismissed after a series of filing abnormalities led to allegations of wrongdoing against her and the candidate.

The case against Marks has the same court docket number as listed for Santos' case.

Santos pleaded not guilty to 13 federal charges -- seven counts of wire fraud, three counts of money laundering, one count of theft of public funds, and two counts of making materially false statements to the US House of Representatives -- in the same courtroom in May.