The US-based strategy and technology consulting firm Booz Allen Hamilton, the former employer of US defector Edward Snowden, is struggling with a second major personnel scandal in three years.
The US Department of Justice announced on Wednesday that Harold Thomas Martin, an employee at the company, has been charged with stealing highly classified documents and codes which were developed by the agency to break into the networks of foreign governments.
"A large percentage of the materials recovered from Martin's residence and vehicle bore markings indicating that they were property of the United States and contained highly classified information of the United States," the Justice Department said in a statement on Wednesday.
The FBI secretly arrested Martin in August and began to investigate whether he stole the codes to hack into the computers of US adversaries such as Russia and China.
Booz Allen Hamilton said in a statement that it fired him immediately after they learned of his arrest. Martin's motive for stealing the data and documents is currently unknown.
The incident marks the second major embarrassment for the company after Edward Snowden disclosed a massive amount of National Security Agency (NSA) documents regarding the agency's previously hidden surveillance programmes.
John Carlin, the Justice Department's chief national security prosecutor, also refused to comment on the specifics of the case.
"I'm sure the trusted professionals I work with across the community will take a hard look at anything they can learn from this case, whether it's about contractors or other issues to see whether they can better defend our systems from others who might try to steal from them," Carlin said in a televised interview with CSPAN.
If Martin is convicted he will face a maximum sentence of one year in prison for "the unauthorised removal and retention of classified materials, and ten years in prison for theft of government property," according to the statement from the Justice Department.
NSA General Counsel Glenn Gerstell told Reuters that the agency was trying to assess the damage from the data theft, but said "I don't think this is a Snowden-type situation."