Updated

The evidence surrounding the case of former NSA contractor Edward Snowden suggests he did not act alone when he downloaded some 200,000 documents, according to the Republican head of the House Intelligence Committee.

"We know he did some things capability-wise that was beyond his capabilities. Which means he used someone else's help to try and steal things from the United States, the people of the United States. Classified information, information we use to keep America safe,"  Rep. Mike Rogers, R-Mich., told Fox News.

Rogers, who receives regular briefings and has access to classified information about the Snowden investigation, says there are questions about the former contractor's time in Hong Kong, and his alleged contact with a third party.

"There was some activity there in China about who he talked to and what was the purpose of his visit there, how was it arranged, how did he arrange a visa so quickly to Russia? Those kinds of questions have not been answered in a satisfactory way."

But journalist Glenn Greenwald -- who published Snowden's leaks – described Rogers' claims as baseless.

An e-mail from Greenwald to Fox News reads in part: "Until he offers actual evidence, rather than his empty assertions, everyone should treat this claim as the unreliable and unconfirmed propaganda that it is. Defenders of domestic surveillance can't keep their story straight: one minute they say Snowden is a brilliant mastermind...and the next minute they say he is a dunce who must have had help."

After that initial e-mail exchange, Greenwald came back to Fox News, saying, "I contacted Snowden, who confirms that he 'acted alone and without outside assistance of any kind.'"

A review of the NSA leaks by Fox News shows the majority of the leaks since June now deal with sources, methods and surveillance activities overseas, rather than the privacy rights of American citizens.

Against this backdrop, already-leaked documents from Snowden and the threat of more were described Sunday as crippling.

"This is catastrophic for the safety and the security of the American nation what this very narcissistic young man has done,” former NSA and CIA Director Michael Hayden said on “Fox News Sunday.”