Natalie Mayflower Sours Edwards, a former senior adviser at the Treasury Department's Financial Crimes Enforcement Network, was charged in October 2018 with leaking "highly sensitive information" about suspects in special counsel Robert Mueller's high-profile investigation into Russia's meddling in the presidential election.
SARs are filed by banks and other financial institutions to alert law enforcement to potentially illegal transactions.
The unlawful disclosures by Edwards occurred between October 2017 and her arrest a year later, according to federal prosecutors. At the time of her arrest, Edwards was in possession of a flash drive that contained the leaked SARs and a cellphone containing numerous communications over an encrypted app where she transmitted the SARs and other sensitive government information to the reporter.
BuzzFeed published a dozen articles as a result of the communication.
Edwards pleaded guilty to one count of conspiracy to make unauthorized disclosures of SARs Monday in the Southern District of New York and is expected to be sentenced on June 9, prosecutors announced in a press release.
The charge carries a maximum sentence of five years in prison.
ABC News' Karma Allen contributed to this report.