Police assembled in Dighton, Massachusetts near the home of Teixeira on Thursday, April 13, 2023. (AP)

Following the breach that is believed to be the most serious security breach to the United States in years, the identity of the source of the leaked US Pentagon documents has come to light.

21-year-old Airman 1st Class Jack Teixeira was arrested Thursday at his house in Dighton, Massachusetts, by heavily armed FBI agents.

Video images circulated on news channels showed heavily armed officers in Massachusetts accompanying a young man into a waiting car.

BREAKING: US intelligence leaker Jack Teixeira, a 21-year-old member of the Air National Guard, is arrested at his home in Massachusetts. pic.twitter.com/vZ2y6d3Fqd
— 301 Military (@301military) April 13, 2023

The Washington Post published an exclusive piece late Wednesday that presented a description of the guy behind the leaks, and provided insight into how the disclosures came to be. The story was based mostly on the information given by a minor who first met the leaker online four years ago in a Discord server for fans of the YouTuber Oxide.

Teixeira is expected to face Espionage Act charges, since Attorney General Merrick Garland previously stated that the military man was detained for allegedly “unauthorized removal, retention and transmission of classified national defense information.”

Teixeira's first court appearance is slated on Friday in the US District Court for the District of Massachusetts.

The media frenzy has shifted the attention to the alleged leaker and away from the damning documents - which include information on Ukraine, China, and the Middle East.

Read more: Mossad backed Israeli anti-govt protests: Leaked Pentagon documents