Washington (CNN) Paul Manafort and Rick Gates' case has added a new criminal charge or charges as of Wednesday, though whether the action is additional grand-jury approved indictments or indicates a coming a plea agreement remains a mystery.

A record-keeping book in the federal courthouse in Washington included a new sealed filing in Manafort and Gates' case, which was opened in late October when the former Trump campaign advisers pleaded not guilty to money laundering and failure to properly disclose their foreign lobbying work. The filing contained no additional information.

The filing could indicate additional indictments in the case, or it could be a type of charge called a criminal information, which would indicate an agreement between prosecutors and a defendant.

Prosecutors on Manafort's case said on Friday they found evidence of bank fraud and related conspiracies, for which Manafort had not been charged.

CNN has also reported that Gates has spoken to prosecutors about his case and has been negotiating a plea deal for more than a month. It's still unclear this week whether he is closer to finalizing an agreement. Both Manafort and Gates maintain their not guilty pleas.

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