Glenn Greenwald, the Guardian journalist who was the first to report on classified documents leaked by Edward Snowden, says the former National Security Agency contractor has what amounts to an "instruction manual for how the NSA is built."
Greenwald made the comments in a Sunday interview with The Associated Press.
Greenwald told the AP that if Snowden were to release those documents, they would "allow somebody who read them to know exactly how the NSA does what it does, which would in turn allow them to evade that surveillance or replicate it."
He added: "In order to take documents with him that proved that what he was saying was true, he had to take ones that included very sensitive, detailed blueprints of how the NSA does what they do."
In an earlier interview with Argentina's La Nacion, Greenwald said that Snowden could cause immense damage to the United States with some of the documents but "that's not his goal."
Snowden is still stranded in Moscow, with the U.S. working hard to extradite him. As Mark reported Friday, Snowden said he was seeking temporary asylum in Russia. Bolivia, Nicaragua and Venezuela have all offered him asylum.