A US Treasury Department official has been criminally charged with leaking confidential documents relating to former Trump campaign chairman Paul Manafort, the Russian embassy and others, to a reporter from digital media company BuzzFeed.

Key points: Ms Edwards is alleged to have sent photos of confidential documents to BuzzFeed reporters

Ms Edwards is alleged to have sent photos of confidential documents to BuzzFeed reporters Prosecutors said the leaks began in October 2017

Prosecutors said the leaks began in October 2017 They say she had a flash drive containing the documents when she was arrested

Natalie May Edwards, a senior adviser in the Treasury Department's Financial Crimes Enforcement Network (FinCEN), was arrested and charged with unauthorised disclosure of suspicious activity reports and with conspiracy, according to the office of US Attorney Geoffrey Berman.

Both charges carry a maximum sentence of five years in prison.

Ms Edwards, 40, was expected to make an initial appearance in Virginia federal court later in the day.

A lawyer for Ms Edwards could not immediately be reached for comment.

Banks must file suspicious activity reports with the Treasury Department when they spot transactions that raise questions about possible financial misconduct such as money laundering.

When federal agents confronted Ms Edwards this week, she described herself as a whistleblower and said she had provided the reports to the reporter for "record-keeping," the court papers said.

Mr Berman said Edwards "betrayed her position of trust by repeatedly disclosing highly sensitive information".

Ms Edwards is alleged to have taken photographs of the confidential documents and sent them to a reporter using an encrypted messaging app, according to court documents.

Ms Edwards also sent the reporter internal Treasury Department emails, investigative memos and intelligence assessments, prosecutors allege.

When she was arrested, Edwards was in possession of a flash drive containing the confidential reports, prosecutors said.

Prosecutors said beginning in October 2017, Ms Edwards disclosed suspicious activity reports connected to Manafort and his longtime associate Rick Gates, accused Russian agent Maria Butina, the Russian embassy and a unit of Prevezon Holdings Ltd, a corporation owned by Russian businessman Denis Katsyv.

Manafort was convicted in August of tax and bank fraud charges, and in September pleaded guilty to a separate conspiracy charge, agreeing to cooperate with authorities in the Russia investigation.

The charges against Manafort involve conduct predating Mr Trump's campaign.

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Gates pleaded guilty in February to conspiracy and making false statements to investigators, also agreeing to cooperate. Ms Butina was jailed in July while she awaits trial.

The disclosures were reported in a series of articles in BuzzFeed related to Special Counsel Robert Mueller's investigation of possible coordination between US President Donald Trump's 2016 election campaign and Russia, according to prosecutors.

The most recent article appeared on Monday and centred on a loan made by TD Bank to Prevezon, citing records uncovered by FinCEN in connection with investigations by Congress and Mueller.

"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.

Court papers also list another FinCEN employee as a co-conspirator, noting that this person exchanged more than 300 messages with the reporter via an encrypted messaging application.

This person has not been charged and was not named in the court papers, and was identified only as an associate director at FinCEN to whom Edwards reported.

Matt Mittenthal, a spokesman for BuzzFeed, had no immediate comment and FinCEN did not immediately respond to a request for comment.

Reuters