A former US government contractor who pleaded guilty to mailing a classified report to a news organisation has been sentenced to more than five years in prison as part of a deal with prosecutors.

Reality Winner, 26, pleaded guilty in June to a single count of transmitting national security information.

The former Air Force translator worked as a contractor at a National Security Agency (NSA) office in Augusta, Georgia, when she printed a classified report and left the building with it. Winner told the FBI she mailed the document to an online news outlet.

In court on Thursday, Winner apologised and acknowledged that what she did was wrong, taking responsibility for “an undeniable mistake that I made”.

“I would like to apologise profusely for my actions,” she told the judge. “My actions were a cruel betrayal of my nation’s trust in me.”

Authorities never identified the news organisation.

The Justice Department announced Winner’s June 2017 arrest the same day The Intercept reported on a secret NSA document.

It detailed Russian government efforts to penetrate a Florida-based supplier of voting software and the accounts of election officials ahead of the 2016 US presidential election.

The NSA report was dated May 5, the same as the document Winner had leaked.

US intelligence agencies later confirmed Russian meddling.

Longest sentence ever imposed

The judge’s sentence was in line with a plea agreement between Winner’s defence team and prosecutors, who recommended she serve five years and three months behind bars.

Prosecutors said in a court filing that punishment would amount to “the longest sentence served by a federal defendant for an unauthorised disclosure to the media”.

Among other leak cases cited by prosecutors in court documents, the stiffest prior sentence was three years and seven months in prison given to former FBI explosives expert Donald Sachtleben.

Secret information he leaked included intelligence he gave to The Associated Press news agency for a story about a US operation in Yemen in 2012.

Winner spent a year in jail before reaching a plea agreement with prosecutors.

Her lawyers had argued for Winner to be released on bond, noting she had no criminal record and had served honourably in the military.

The judge sided with prosecutors who said Winner posed a potential flight risk and may have stolen other classified documents.

Prosecutors also used Winner’s own words against her, including a Facebook chat in which she once wrote to her sister: “Look, I only say I hate America like 3 times a day.”

Despite prosecutors’ warnings that Winner may have stolen other US secrets, she was never charged with any additional crimes.

Winner grew up in Kingsville, Texas, and enlisted in the Air Force after graduating from high school. Her parents said she became a linguist, speaking Arabic and Farsi, and spent four years assigned to the NSA at Fort Mead, Maryland. During that time, Winner provided real-time translation to Americans conducting field missions.

After leaving the military, Winner moved to Augusta to become a civilian contractor for the NSA.

Court records say Winner translated documents from Farsi to English for the agency.