• Rogers: Snowden 'a thief whom we believe had some help' • Feinstein adds voice to criticism of Obama NSA speech

Russia may have helped the former National Security Agency contractor Edward Snowden to reveal details of surveillance programmes and escape US authorities last year, the chairman of the House intelligence committee claimed on Sunday.

Mike Rogers, a Republican representative from Michigan, interviewed by NBC’s Meet the Press, said Snowden was “a thief whom we believe had some help”, and added that there was an “ongoing” investigation into whether Russia had aided Snowden.

“I believe there's questions to be answered there,” Rogers said. “I don't think it was a gee-whiz luck event that he ended up in Moscow under the handling of the [Russian intelligence service] FSB.”

Rogers added: “Let me just say this. I believe there’s a reason he ended up in the hands, the loving arms, of an FSB agent in Moscow. I don’t think that’s a coincidence.

“We have questions that we have to answer but as someone who used to do investigations some of [the] things we are finding we would call clues that certainly would indicate to me that he had some help and he stole things that had nothing to do with privacy,” said Rogers.

The Democratic chair of the Senate intelligence committee, Dianne Feinstein, a staunch defender of the NSA’s programmes, also spoke to Meet the Press. She said Snowden had joined the NSA “with the intent to take as much material down as he possibly could”.

Asked if he was aided by the Russians, Feinstein said: “He may well have. We don’t know at this stage. But I think to glorify this act is to set a new level of dishonour.”

Rogers' comments were backed by Michael McCaul, chairman of the House committee on homeland security. Speaking from Moscow, the Texas Republican told ABC’s This Week: “I believe he [Snowden] was cultivated by a foreign power to do what he did.”

McCaul said he could not “definitively” say it was Russia that helped Snowden. “Hey, listen, I don't think … Mr Snowden woke up one day and had the wherewithal to do this all by himself. I think he was helped by others. Again, I can't give a definitive statement on that … but I've been given all the evidence, I know Mike Rogers has access to, you know, that I've seen that I don't think he was acting alone.”

Snowden was granted temporary asylum in Russia last August, after travelling to Moscow from Hong Kong. Last year, in an interview with the New York Times, Snowden said he did not take any of the documents he obtained to Russia, “because it wouldn’t serve the public interest”.

Snowden said there was “zero-percent chance” that Russia had received any documents and that he had handed all his NSA data to journalists from media outlets including the Guardian, before leaving Hong Kong. “What would be the unique value of personally carrying another copy of the materials onward?” he said.

Snowden has consistently denied any involvement with foreign spying agencies and said he leaked the documents because he believed the NSA programmes were against the best interests of the US people.

“I don't want to live in a society that does these sort of things,” he told the Guardian last year.

Rogers did not give any supporting evidence for his claims, but suggested Snowden “used methods beyond his technical capabilities" and had help with his travel arrangements.

“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,” Rogers said.

Mike Rogers is chair of the House intelligence committee. Photograph: AP

Rogers' comments came after President Barack Obama on Friday outlined possible reforms to surveillance practices and a review of the NSA’s programmes. The speech met with a mixed reaction from privacy advocates and tech and telecoms companies, all of whom said there was too little detail and little clarity on how or if the system was being reformed.

The NSA revelations have also damaged relations with countries including Brazil and Germany, where the US has been accused of spying on its allies. On Sunday, Brazil gave Obama's speech a cautious welcome.

"It's a first step. The Brazilian government will monitor the practical ramifications of the speech very closely," president Dilma Rousseff's spokesman, Thomas Traumann, wrote on the president's official blog.

Some Democrats have been critical. Senator Patrick Leahy, chairman of the Senate judiciary committee, told Fox News Sunday further checks and balances were needed. “There’s a concern that we have gone too much into Americans’ privacy,” he said. “There’s still going to be legislation on this.”

In his speech, Obama said he wanted bulk phone data to be stored outside the government, to reduce the risk that such records would be abused; that he would require a special judge's advance approval before agencies could examine an individual's data; and that he would force analysts to keep their searches closer to suspected terrorists or organisations.

On Sunday, Feinstein said: "I think that's a very difficult thing. Because the whole purpose of this program is to provide instantaneous information to be able to disrupt any plot that may be taking place."

Rogers was also critical of Obama. He told CNN’s State of the Union the president's speech had created more uncertainty in the intelligence community and was potentially dangerous.

“We really did need a decision on Friday and what we got was lots of uncertainty,” he said. “And just in my conversations over the weekend with intelligence officials, that level of uncertainty is already having a bit of an impact on our ability to protect Americans by finding terrorists trying to reach into the United States.”

He added: “I just don’t think we want to go to pre-9/11 just because we haven’t had an attack.”