Rep. George Santos' (R-NY) campaign treasurer Nancy Marks has agreed to plead guilty to federal charges, according to court records.

The Associated Press reported the news, saying that the case continues to be under seal so it's unknown if it is part of a cooperation agreement or plea deal with prosecutors. The records only indicate she waived an indictment and would plead guilty.

Marks resigned from Santos' team in January after there were many reports of strange campaign spending and names of donors who didn't appear to exist. A campaign treasurer is the one who signs the filings – with the understanding that they will do the proper compliance to ensure the campaign or candidate is following the law.

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"Santos blamed Marks when questions were raised about the sources of his fundraising and his spending," ABC News reported. "The Republican congressman pleaded not guilty in May to a 13-count indictment accusing him of fraud, money laundering and theft of public funds."

"If pursuant to a cooperation agreement (which I suspect it is), this is very bad for George Santos. It likely means more campaign finance fraud charges to come," pointed out Rep. Dan Goldman (D-NY).