A National Security Agency contractor has been detained, accused of taking top secret information, officials say.
Harold Thomas Martin III is charged with larceny of government property and unauthorised removal of “highly classified” materials.
The 51-year-old had a top secret national security clearance and faces 10 years in prison.
The lawyer of Mr Martin said there was no signs he’d betrayed the US, a nation he very much loved.
The Justice Department said he worked for Booz Allen Hamilton, exactly the same contractor that applied NSA leaker Edward Snowden.
Six of the documents found in Mr Martin’s possession were classified as top secret, “meaning that unauthorized disclosure reasonably could be expected to cause exceptionally grave damage to the national security of the US”, the Justice Department said.
In accordance with a warrant, Mr Martin was detained two days after his Glen Burnie, Maryland, dwelling, garage and vehicle were searched on 27 August this year.
The FBI said Mr Martin denied taking the records, but after acknowledged removing documents and digital files.
Mr Martin’s lawyer, James Wyda, told the Baltimore Sun his customer has yet to be proven guilty.
“There’s no signs that Hal Martin has betrayed his nation,” Mr Wyda said.
“What we do understand is that Hal Martin loves his family and his nation. He served this nation honourably in the US Navy and he has given his entire life to protecting his country.”
The New York Times, which broke the story, said Mr Martin was suspected of taking the NSA’s “source code” used to hack into the systems of Russia, China, Iran and North Korea.
“A large percentage of the substances recovered from Martin’s residence and vehicle bore markings indicating that they were property of the United States and featured highly classified information of the USA,” FBI Special Agent Jeremy Bucalo wrote.
“The disclosure of the records would show those sensitive sources, procedures, and abilities.”
John Carlin, the top national security official of the Justice Department, said the arrest underlined the danger posed by insiders.