WASHINGTON – A top congressional intelligence official said Sunday that U.S. counterintelligence officials are virtually unanimous in believing that Edward Snowden is "under the influence of Russian intelligence services."

That suggestion came from Rep. Mike Rogers, R-Mich., chairman of the Intelligence Committee.

Rogers had previously raised the possibility that Snowden, the former National Security Agency contractor, might be working for Russia, though the congressman has yet to offer any evidence. His assertions Sunday, however, were his most sweeping to date.

"Every counterintelligence official believes that," Rogers said on the NBC News program "Meet the Press." "You won't find one that doesn't believe today he's under the influence of Russian intelligence services."

For Rogers, the question now is when that supposed collaboration began: after Snowden arrived in Moscow from Hong Kong in late June, or before then, when he abruptly left Hawaii in May.

"The more we look into this, I think the more you're going to find that that date gets further and further away from his story," Rogers said.

In a Jan. 19 appearance on the same NBC program, Rogers said some of Snowden's actions in absconding with secret NSA materials were "beyond his technical capabilities."

But investigators have disclosed no evidence that Snowden's work, while under contract to the NSA, might have been directed by a foreign power.

Ben Wizner, an American Civil Liberties Union lawyer who advises Snowden, has vigorously rejected Rogers' contentions, noting that Snowden tried to gain asylum in several other countries before settling in Russia.

There has been no public indication that investigators for the FBI, the NSA or the Pentagon have uncovered evidence that Snowden received assistance from any foreign intelligence service.