The justice department has released the charging documents against Jack Teixeira, a 21-year-old member of the intelligence wing of the Massachusetts Air National Guard who faces two counts related to the leaking of hundreds of US classified documents on a gaming chat server.

He is facing two separate counts: The unauthorised retention and transmission of national defence information and the unauthorised removal and retention of classified documents or material.

Airman Teixeira, who was charged in federal court in Boston on Friday, will be detained till his detention hearing on Wednesday.

In an 11-page complaint, an FBI agent with the bureau’s counterintelligence division in Washington detailed much of what has already been reported publicly — that Airman Teixeira posted sensitive national security documents bearing top secret markings to a Discord chat group identified in court papers as “Social Media Platform 1”.

Airman Teixeira was arrested in Massachusetts, and attorney general Merrick Garland indicated that he was likely to face charges under the Espionage Act.

The trove of leaked classified American documents, some of which were barely 40 days old, discussed weaknesses in the Ukrainian military and exposed the ability of US surveillance to penetrate Russian communications systems. They included maps of Ukrainian air defences and documents that paint a picture of the Russian government feuding internally over the war’s casualty count.