WASHINGTON — The heads of the House and Senate intelligence committees suggested Sunday that Edward J. Snowden, the former National Security Agency contractor, may have been working for Russian spy services while he was employed at an agency facility last year and before he disclosed classified government documents.
The lawmakers, Representative Mike Rogers, Republican of Michigan, and Senator Dianne Feinstein, Democrat of California, offered no specific evidence that Snowden cooperated with Moscow, but they said the fact that he has ended up in Russia raises significant questions.
So far, there has been no public indication that the FBI’s investigation into Snowden’s actions, bolstered by separate “damage assessment” investigations at the NSA and the Pentagon, has uncovered evidence that Snowden received help from a foreign intelligence service.
Feinstein and Rogers appeared Sunday on NBC’s ‘‘Meet the Press.’’ Rogers also appeared on CNN’s ‘‘State of the Union’’ and CBS’s ‘‘Face the Nation.’’
In their interviews, the lawmakers also said that a chief element of President Obama’s attempt to overhaul US surveillance probably will not work.
Obama said Friday that he wants bulk phone data stored outside the government to reduce the risk that the records will be abused. The president said he will require a special judge’s advance approval before intelligence agencies can examine someone’s data and will force analysts to keep their searches closer to suspected terrorists or organizations.
‘‘And I think that’s a very difficult thing,’’ said Feinstein, who chairs the Senate Intelligence Committee. ‘‘Because the whole purpose of this program is to provide instantaneous information to be able to disrupt any plot that may be taking place.’’
Under the surveillance program, the NSA gathers phone numbers called and the length of conversations, but not the content of the calls. Obama said the NSA sometimes needs to tap those records to find people linked to suspected terrorists. But he said eventually the bulk data should be stored somewhere out of the government’s hands.
That could mean finding a way for phone companies to store the records, though some companies have balked at the idea, or it could mean creating a third-party entity to hold the records.
Feinstein said many Americans don’t understand that threats persist a dozen years after the 9/11 terrorist attacks. ‘‘New bombs are being devised. New terrorists are emerging, new groups. Actually, a new level of viciousness. And I think we need to be prepared,’’ she said.
Rogers, chairman of the House Intelligence Committee, said Obama had intensified a sense of uncertainty about the country’s ability to root out terrorist threats. Obama didn’t specify who should have control of Americans’ phone data; he directed the attorney general and director of national intelligence to find a solution within 60 days.
‘‘We really did need a decision on Friday, and what we got was lots of uncertainty,’’ Rogers said. ‘‘And just in my conversations over the weekend with intelligence officials, this new level of uncertainty is already having a bit of an impact on our ability to protect Americans by finding terrorists who are trying to reach into the United States.’’
In his comments on Snowden’s possible ties to Russian spy agencies, Rogers referred to a recent classified report by the Defense Intelligence Agency that he has described in other interviews as concluding Snowden stole approximately 1.7 million intelligence files that concern vital operations of the US Army, Navy, Marine Corps, and Air Force. The defense intelligence report is classified, but some members of Congress have been briefed on it.
“I believe there’s questions to be answered there,” Rogers said on the NBC program. “I don’t think it was a gee-whiz luck event that he ended up in Moscow under the handling of the FSB,” he said, referring to the Federal Security Service, the Russian state security organization that succeeded the KGB.
Feinstein, when asked whether she agreed with Rogers that Snowden may have had help from the Russians, was more tentative: “He may well have. We don’t know at this stage.”
Both lawmakers said their committees would continue to pursue these suspicions.
Snowden has been living in Russia since June. He has said that he did not take any secret NSA documents with him to Russia when he fled there, ensuring that Russian intelligence officials could not get access to them.
Ben Wizner, an American Civil Liberties Union lawyer who advises Snowden, said in a telephone interview that the accusation that Snowden had been recruited by Russian spy services before he left his NSA job in Hawaii last year was “not only false, it is silly.”
Wizner also criticized Rogers’s description of the defense agency report as “exaggerated national security claims.”
A senior official with access to the intelligence on Snowden said that U.S. suspicions had been raised in part because of changes that have taken place in information that Snowden is believed to have stored since he left the United States.
Investigators believe that data is being stored by an Internet cloud service, though it is unclear who has access to it. The United States is concerned that Russian agents may have access to the data while Snowden is in the country under temporary asylum, or in exchange for his asylum.
“Something more was going on there, and because of the nature of the information that was stolen,” Rogers said on CBS, adding that it had “nothing to do with Americans’ privacy, a lot to do with our operations overseas.”