A US Air National Guardsman is to appear in court on Friday in Boston, Massachusetts, charged in connection with a leak of classified US military intelligence on the war in Ukraine.
Ednews reports citing US media that Jack Teixeira, 21, was arrested by the FBI at his family home in Dighton, rural Massachusetts, on Thursday.
Dressed in shorts and T-shirt, he was led away as news helicopters hovered.
Airman Teixeira has been identified as the leader of an online chat group where the documents first emerged.
He is charged with the unauthorised removal and transmission of classified information.
The leaks revealed US assessments of the war in Ukraine, as well as sensitive secrets about American allies, embarrassing Washington and posing risks to national security.
Airman Teixeira worked as an IT specialist in the intelligence wing of the Massachusetts National Guard, based at Otis Air National Guard Base in western Cape Cod.
Separately, he oversaw an online chat room made up mainly of male teenagers, with whom he had allegedly been sharing top secret information for months.
It was not until intelligence material was posted outside the chat room group that Pentagon officials became aware of the leak, prompting a massive search for the culprit.
Aside from the age of the suspect, the motive is also thought to be unusual.
While Airman Teixeira is said to have harboured a scepticism of government, friends said he was neither a whistle-blower nor a foreign agent.
He joined the National Guard in 2019, according to his service record, obtained by the BBC's US partner, CBS News.
His official title is Cyber Transport Systems journeyman and he holds the rank of Airman 1st Class - a relatively junior position.
The Pentagon says it will re-examine how classified information is distributed, but a spokesman said it was "the nature" of the US military to entrust young service members with high levels of responsibility.
