A Treasury Department employee was arrested on Tuesday for allegedly leaking to the press sensitive government documents related to special counsel Robert Mueller’s investigation of Russia and the 2016 U.S. election, the Justice Department said.

Federal prosecutors in Manhattan charged senior Treasury advisor Natalie Mayflower Sours Edwards with two counts involving “unauthorized disclosures” of Suspicious Activity Reports, which are kept by the department’s Financial Crimes Enforcement Network (FinCEN).

The reports contained financial information about former Trump campaign chairman Paul Manafort, his former business partner Richard Gates, accused Russian spy Maria Butina, the Russian Embassy, and Prevezon, a Russian-owned company accused by the U.S. of money laundering. Financial institutions are required to flag potentially illegal transactions in Suspicious Activity Reports (SARs).

While the complaint does not name the news organization allegedly in contact with Edwards, it references articles BuzzFeed published citing the Suspicious Activity Reports, including “Secret Finding: 60 Russian Payments to Finance Election Campaign of 2016” and “Russian ‘Agent’ and a GOP Operator Left a Trail of Cash, Documents Reveal.” The complaint accuses Edwards of being a source for 12 BuzzFeed stories in the past year. BuzzFeed declined to comment.

“We hope today’s charges remind those in positions of trust within government agencies that the unlawful sharing of sensitive documents will not be tolerated and will be met with swift justice by this office,” U.S. Attorney Geoffrey S. Berman said in a statement.

“ The fact that we uncovered this scheme is a big win for us. ” — Senior Treasury official

Edwards, 40, allegedly saved the reports onto a flash drive and provided them to an unidentified reporter by taking photos of the documents and then texting them through an encrypted messaging app. She also allegedly sent the reporter internal emails, including investigative memos and intelligence assessments that “contained confidential personal, business, and/or security threat assessments,” according to the complaint.

Authorities found the flash drive and a phone with the BuzzFeed exchanges when they arrested Edwards, according to the complaint.

Treasury officials told The Daily Beast it is highly unusual for an employee, particularly inside FinCEN, to engage with the press—let alone disclose sensitive information like SARs.

Over the past year, officials said Treasury leadership became increasingly frustrated with the leaks that began to appear in BuzzFeed in October 2017 and officials held several meetings to try to determine who inside the department was responsible.

Two Treasury officials told The Daily Beast they worried if the leaks continued it would have a lasting impact on the integrity of FinCEN and its ability to maintain credibility in its investigations into matters such as money laundering and terrorist financing.

Department heads interviewed staffers inside FinCEN about the alleged leaks beginning sometime this year, according to the officials.

“This is really an amazing thing, for someone to have done this and for that person to have gotten caught,” one senior Treasury official said. “This just doesn’t happen here all that often. The fact that we uncovered this scheme is a big win for us.”

Edwards is just the latest government employee to be arrested for allegedly leaking to the media in the Trump administration’s self-proclaimed war on leaks. Under Attorney General Jeff Sessions, leak probes in the Justice Department jumped 800 percent after a total of nine investigations from 2014 to 2016.

This past May, Sessions doubled down on his commitment to root out leakers after President Trump became incensed by anonymous sources sharing White House information with the press, an official told The Daily Beast.

In August, former Air Force intelligence contractor Reality Winner was sentenced to more than five years in federal prison after she pleaded guilty to leaking a top-secret government report to The Intercept. Prosecutors sentenced Winner, 26, to the longest ever punishment imposed in federal court for such a leak. Hers was the first sentencing under the Espionage Act since Trump became president.

This week, a former Senate Intelligence Committee staffer pleaded guilty to lying to the FBI when he denied giving classified information to a New York Times reporter. Federal prosecutors secretly seized years’ worth of phone and email records from the Times’ Ali Watkins, the first time the aggressive tactic is known to have been used against a member of the press to prosecute a source.

Meanwhile, the Treasury Department is apparently still investigating the leak of SARs about Michael Cohen, Trump’s personal attorney.

The reports showed Cohen used a shell company to pay hush money to Trump’s alleged former mistress, Stormy Daniels. Cohen’s shell company also received the $1 million in payments from companies with business before the Trump administration.

In May, the New Yorker published an exclusive interview with a law enforcement agent who shared the reports with the press. The agent said they shared the documents out of concern files about Cohen’s payments may have been withheld from law enforcement after they did not supposedly appear in a government database.

— With additional reporting by Maxwell Tani.