(CNN) -- FBI agents interviewed one of the suspects in the Boston Marathon bombings two years ago, but found no connection with terror groups.
An FBI official said agents interviewed Tamerlan Tsarnaev in 2011 at the request of the Russian government.
"The request stated that it was based on information that he was a follower of radical Islam and a strong believer, and that he had changed drastically since 2010 as he prepared to leave the United States for travel to the country's region to join unspecified underground groups," the FBI said in a statement.
The FBI said it took a number of investigative steps to check on the request, including looking at his travel history, checking databases for derogatory information and searching for Web postings.
Agents also interviewed Tsarnaev's family members, the FBI said, but did not detect terrorist activity.
"The FBI did not find any terrorism activity, domestic or foreign, and those results were provided to the foreign government in the summer of 2011," the FBI's statement said. "The FBI requested but did not receive more specific or additional information from the foreign government."
U.S. Rep. Michael McCaul, R-Texas and chairman of the House Homeland Security Committee, said Friday that information that Tsarnaev had been interviewed by the FBI in the past was disturbing.
"It's new information to me and it's very disturbing that he's on the FBI's radar screen," McCaul told CNN's Erin Burnett.
McCaul praised the FBI's efforts investigating the case since Monday's bombings.
"But if he was on the radar and they let him out of their sights, then that's an issue, certainly, for me," McCaul said.
The suspects' parents told Russian state media that the FBI had been speaking with their sons.
"FBI came to them two or three times, asking 'Are you Chechens? Is anyone harassing you?' Why would anyone offend us? Then they came again. Said they wanted to talk to Tamerlan. We didn't know what was going on, didn't know whether he had done something. But they were saying, 'Oh, it's nothing, it's just routine.' They talked to us at our home," father Anzor Tsarnaev told the state-run RIA Novosti news agency. "I heard myself that they (the FBI) said: 'We know that you read, what you drink, what you eat, where you go.' And then they added that that's routine practice to prevent bombings on the streets of Boston, so that our kids can go to school in peace. This conversation happened half a year ago. But I keep asking, why did they have to talk to him about that then?"
Mother Zubeidat Tsarnaeva told Russia Today that the FBI had been checking on Tamerlan for three to five years.
"They knew what he was doing, what sites he was visiting. They followed his every move, yet today they say this is a terrorist act," she said. "The FBI was afraid of my eldest son because he was a leader, could stand up for himself, and talked about Islam a lot. Once they officially called me and told me that they don't doubt his decency. But at the same time they said he gets information from extremists' sites and that they are very afraid of him."
Earlier Friday, a U.S. official familiar with the latest intelligence information on the Boston Marathon bombings said initial indications were that the two suspects do not have direct links to any major al Qaeda group or affiliates, or to a new significant terrorist threat to the United States.
These are some early assessments but far from final conclusions, the official said. The assessments are part of a full interagency review now under way by the U.S. intelligence and law enforcement community, who are going back through their databases and information looking for any links to the two men.
The intelligence review earlier Friday had focused to a large extent on regional militant connections the men have had in Russia or Central Asia. But the official also noted they simply may have been "inspired" by a militant ideology or may simply have been disgruntled persons aiming to carry out an attack, and had no connections to foreign groups. "We simply don't know yet," he said.
The review was ordered by James Clapper, director of National Intelligence. Initially, before the men were identified by the FBI, the review was looking at any indications of a threat emerging from overseas against the United States. Once the identities of the men became known, with their possible ethnic Chechen background, the focus shifted.
The intelligence community is tasked under the review with checking any intelligence gathered overseas while the FBI will focus on what is known inside the United States.
CNN's Boriana Milanova and Amir Ahmed contributed to this report.