A leading House Republican is raising questions about Russia's involvement in the largest security leak in recent U.S. history.

House Intelligence Committee Chairman Mike Rogers said that former National Security Agency contractor Edward Snowden, who has leaked details of the NSA’s surveillance operations, “was a thief who we believe had some help.”

In an interview to be aired Sunday on NBC’s Meet the Press, Rogers said that rather Snowden being a crusader for Americans’ privacy, “the vast majority” of what Snowden stole “had nothing to do with privacy. Our Army, Navy, Air Force, Marines have been incredibly harmed by the data that he has taken with him and we believe now is in the hands of nation states.”

The Michigan Republican added that there are still “certain questions that we have to get answered” about who helped Snowden remove data from the NSA and later make it public in newspapers in the United States and Britain.

“He was stealing information that had to do with how we operate overseas to collect information to keep Americans safe…. And some of the things he did were beyond his technical capabilities” -- a fact which Rogers said “raises more questions. How he arranged travel before he left. How he was ready to go, he had a go bag, if you will.”

Rogers added that he believes “there's a reason he ended up in the hands, the loving arms, of an FSB (Russian security service) agent in Moscow. I don't think that's a coincidence….I don't think it was a gee-whiz luck event that he ended up in Moscow under the handling of the FSB.”

It was mostly in response to Snowden’s disclosures that President Barack Obama announced Friday some restrictions on how the NSA will collect data and conduct surveillance.

Separately, Bruce Riedel, director of the Intelligence Project at the Brookings Institution in Washington and a former CIA official, said Friday that one key question now in the Snowden affair is “Is it really Edward Snowden who is doing this, or is there a larger apparatus? I know that many people in the intelligence community… now no longer regard Edward Snowden as a thief or a traitor…. They regard him as a defector” who has gone over to a foreign intelligence agency.