Washington: The FBI has arrested a man who worked as a contractor for the National Security Agency in a probe into the possible theft of top-secret codes, US authorities said today.
The Department of Justice released a criminal complaint against Harold Thomas Martin III, 51, of Maryland, charging him with theft of government property and unauthorized removal and retention of classified materials.
He was arrested August 27 following a search of his home. Martin, who has now been fired, worked for Booz Allen Hamilton -- the same firm that hired notorious leaker Edward Snowden.
Booz Allen helps build and operate many of the NSA's most sensitive cyber operations, the New York Times reported. The criminal complaint states that investigators found hard copies and digital files of top secret documents in Martin's home and car.
Six of the documents "were produced through sensitive government sources, methods and capabilities, which are critical to a wide variety of national security issues," the complaint states.
In a statement, Booz Allen said it had reached out to offer full cooperation with authorities as soon as it learned of the arrest. "And we fired the employee," the statement read.
"Booz Allen is a 102-year-old company, and the alleged conduct does not reflect our core values." The NSA did not immediately respond to requests for comment.
Investigators wrote that Martin initially denied charges, but when confronted with the documents, he admitted taking the files and stated that "he knew what he had done was wrong."
Martin's lawyers said in a statement to US media: "We have not seen any evidence. But what we know is that Hal Martin loves his family and his country. There is no evidence that he intended to betray his country."
The arrest came after investigators began looking into the theft of source code used by the NSA to hack adversaries' computer systems -- such as those of Russia, China, Iran and North Korea.
Such access would enable the NSA to plant malware in rivals' systems and monitor -- or even attack -- their networks.
The Times said investigators are still puzzling over a motive for the alleged crimes, and that it did not look like an espionage case.
Unclear too is whether Martin is thought to be behind the leak of classified NSA code that was attributed to a group calling itself the "Shadow Brokers."
Former NSA contractor Snowden has been living in Russia since shortly after leaking documents revealing the scope of the agency's monitoring of private data.