WASHINGTON — Edward J. Snowden on Tuesday adamantly denied as “absurd” and “smears” the suggestion by the leaders of the House and Senate Intelligence Committees that he might have been a Russian spy when he downloaded archives of classified National Security Agency documents and leaked them to journalists.

In an interview with The New Yorker, Mr. Snowden declared that the accusation — advanced in particular by Representative Mike Rogers, Republican of Michigan and chairman of the House Intelligence Committee — was “false,” saying he had “clearly and unambiguously acted alone, with no assistance from anyone, much less a government.”

In the latest jostling over how to frame the public debate that Mr. Snowden’s leaks created, Mr. Rogers said on the NBC News program “Meet the Press” on Sunday that Mr. Snowden should be seen not as a whistle-blower but as “a thief, who we believe had some help.”

Officials at both the N.S.A. and the F.B.I. have said their investigations have turned up no evidence that Mr. Snowden was aided by others. But Mr. Rogers, asserting that Mr. Snowden had downloaded many files about military activities that do not involve issues of civil liberties, pointed to the Russian Federal Security Service, known as the F.S.B., the successor to the Soviet K.G.B. He offered no evidence.