Edwards and a "co-conspirator" who is not named in the complaint "exchanged approximately 301 messages with Report-1".
Bloomberg reports that Natalie Mayflower Sours Edwards, senior adviser at Treasury's Financial Crimes Enforcement Network (FinCEN), has been accused of leaking Suspicious Activity Reports (SARs) to an unidentified reporter at Buzzfeed.
New York-based BuzzFeed has reported extensively on SAR documents connected to Butina, Manafort and others. Hudak and Richard Delmar, a spokesman for the Treasury Department's internal investigative unit, both declined to comment on the allegations involving the associate director.
As well as Manafort, the reports allegedly leaked by Edwards included information on Rick Gates, Trump's former deputy campaign chairman, and Maria Butina, the alleged Russian spy.
Edwards is now on administrative leave, FinCen spokesman Steve Hudak said.
Edwards also had in her possession a thumb drive containing copies of thousands of so-called SARs, the Federal Bureau of Investigation said.
A lawyer for Ms Edwards could not immediately be reached for comment.
Prosecutors said Edwards saved the confidential reports on a flash drive and sent them to the BuzzFeed reporter using an encrypted messaging application.
Authorities say Edwards has been charged with one count of unauthorized disclosures of SARs and one count of conspiracy to make unauthorized disclosures of suspicious activity reports.
Edwards had worked from 2007 to 2010 in the human resources and professional development office at the Bureau of Alcohol, Tobacco, Firearms and Explosives, spokeswoman April Langwell said.
Edwards was questioned by Federal Bureau of Investigation agents Tuesday in Virginia as they carried out a court-ordered search warrant to access her cellphone and to search her personally.
In January 2017, BuzzFeed also published a series of unverified memos alleging that Russian Federation has damaging and salacious information about President Trump, who's called it the "Fake Dirty Dossier".
The court documents also indicate the FBI has investigated one of Edwards's bosses, an associate director of FinCEN, noting that person exchanged 325 text messages with the reporter in question during the month when the first story appeared citing SARs reports. The court papers do not name the reporter or the media outlet.
According to court papers, federal investigators obtained a court order to monitor the calls to and from the associate director's personal cellphone, and the monitoring captured the frequency of contacts with the reporter via the encrypted messaging application. Court papers do not detail the contents of those messages.
"Protecting sensitive information is one of our most critical responsibilities, and it is a role that we take very seriously", said Sigal Mandelker, the Treasury Department's undersecretary for terrorism and financial intelligence.