ATLANTA (CNN) — Russia intercepted a communication between the mother of the accused Boston Marathon bombers and someone who may have been one of her sons "discussing jihad" in 2011, according to a U.S. official with knowledge of the investigation.
This source described the conversation as vague.
The Russians turned over the intercept to the FBI in the last few days, the official said.
This source was not aware of a reason for the delay and did not offer an opinion about whether it would have given the FBI enough reason to justify a closer look at Tamerlan Tsarnaev, the oldest of the two brothers.
U.S. Attorney General Eric Holder was asked abut the report while attending the White House Correspondents Dinner Saturday.
"That's an ongoing matter," Holder said. "I can't really comment on that."
CNN has previously reported that the FBI has said that it conducted an investigation -- including an interview with Tamerlan Tsarnaev after Russia expressed concerns in 2011.
The FBI said at the time if found nothing to justify pursuing the matter further and that Russia did not respond to US requests for additional information.
The Russians also raised questions about Tsarnaev's mother, Zubeidat Tsarnaev, when they approached the U.S. about concerns regarding Tamerlan Tsarnaev, according to several sources. The mother's name was subsequently added to the TIDE (Terrorist Identities Datamart Environment) database at at the same time as her son's, an intelligence official said Thursday. TIDE is a collection of more than half million names of suspected terrorists that is maintained by the National Counterterrorism Center.
The FBI did interview the mother in 2011 as part of the investigation into her son. The case was closed after several months.
Attorney General Holder also responded to criticism that the surviving suspect Dzhokhar Tsarnaev was read his Miranda rights not to be questions without a lawyer.
"The decision to Mirandize him was one that the magistrate made and that was totally consistent with the laws that we have," Holder said. "We have a two-day period to question him under the public safety exception. So I think everything was done appropriately and we got good leads."
FBI: Search of dump tied to suspect ends
Twelve days after a pair of blasts turned celebratory cheers into screams of horror at the Boston Marathon's finish line, investigators continued working -- interviewing people and searching for evidence, even when it meant sifting through trash -- to find out why.
One of the latest focuses of the probe has been a landfill in New Bedford, Massachusetts, a city adjacent to the town where the surviving bombing suspect, Dzhokhar Tsarnaev, attended school at the University of Massachusetts-Dartmouth.
Authorities have finished combing the dump for clues that may shed light on the bloody attack, said FBI spokeswoman Laura Eimiller, who wouldn't say whether they turned up anything.
That includes any luck in locating Tsarnaev's laptop computer, which a law enforcement official with knowledge of the investigation had said investigators were looking for.
Tsarnaev led authorities to look there, the source said, and others who may have knowledge of the computer's whereabouts or may have played a role in disposing it also provided leads that prompted the search.
The boat -- located in the backyard of a Watertown, Massachusetts, home -- where Tsarnaev was captured has been taken to an undisclosed location, to be thoroughly examined, according to the FBI.
Eimiller, the FBI spokeswoman, said the investigation overall remains open, with interviews continuing as well as the search for evidence.
The 19-year-old suspect himself spent Saturday at the Federal Medical Center in Fort Devens, the federal inmate medical center to which he was transferred from Boston's Beth Israel Deaconness Medical Center early Friday morning.
He had what appeared to be gunshot wounds to his head, neck, legs and hand when he was captured April 19 after a nearly 24-hour manhunt, according to the criminal complaint accusing him in the marathon blasts. His 26-year-old brother Tamerlan died after a gunfight hours earlier.
Dzhokhar Tsarnaev has been less talkative since authorities read him his Miranda rights before charging him with using a weapon of mass destruction, which happened three days after his capture.
But the information the teenager gave investigators in two sessions of questioning spanning those three days has produced good leads, a U.S. law enforcement official said.
Family in Russia
The brothers' mother said Friday that she and her husband had left their home in Dagestan for another part of Russia.
Their father, Anzor Tsarnaev, had said he'd planned to travel to the United States. But that trip has been delayed indefinitely for health reasons.
The mother will not be flying to the United States, where she is wanted on felony charges of shoplifting and destruction of property.
The family lived in Massachusetts before Zubeidat Tsarnaev jumped bail after her arrest on the charges in 2012. The parents moved to Dagestan, a semiautonomous republic in southern Russia that year.
Russian authorities twice raised concerns in 2011 to U.S. authorities about the mother and her older son, sources said.
U.S. authorities added both their names to the Terrorist Identities Datamart Environment, or TIDE, database, which includes half a million names.
Zubeidat Tsarnaev has denied the reality of the bombing. She believes it was fake. She said she has seen a video pushing the wild idea, and that there was no blood, that paint was used instead.
While insisting Russian and U.S. authorities often work together, Russian President Vladimir Putin has said that he wished U.S. authorities could have done more to prevent the Boston attack.
But he also lashed out against those in the West who have slammed Russia for human rights abuses in its actions toward Chechnya, the Tsarnaevs' original war-torn homeland.
Botched hijacking thwarts plans to head to NYC
Three days after the Marathon attack, and hours after authorities released images of the two suspects, they spontaneously decided to go to New York's Times Square to blow up their six remaining explosives, Dzhokhar Tsarnaev told investigators.
But a botched carjacking spoiled the impromptu road trip, said Tsarnaev, whose account was outlined by New York's police commissioner.
Before forcing their way into a vehicle the night of April 18, the brothers shot dead a campus police officer at the Massachusetts Institute of Technology, police said.
The vehicle they subsequently hijacked, a Mercedes SUV, ran low on fuel, and they stopped at a service station, where the vehicle's owner escaped. Shortly thereafter, police picked up the trail of the SUV and pursued it. Authorities say the men threw bombs out the vehicle's window at them. The gun battle and Tamerlan Tsarnaev's death followed.