Three people were killed and about 260 wounded on April 15 last year when two bombs made of explosives-packed pressure cookers went off near the finish line of the marathon.
US authorities are seeking the death penalty for Dzhokhar Tsarnaev, then 19, for his alleged role in the blasts. His brother Tamerlan, 26, died after an exchange of fire with police after the Chechen Muslim brothers went on the run, sparking a four-day manhunt.
Citing an inspector general's review of how American intelligence and law enforcement agencies could have thwarted the bombing, the Times said that Russian officials told the FBI in 2011 that Tamerlan "was a follower of radical Islam and a strong believer."
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
The Russian side said that Tamerlan "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."
But, according to The Times, after an initial investigation by FBI agents in Boston, the Russians declined several requests for additional information they had about him.
The inspector general's report found that it was only after the bombing that the Russians shared the additional intelligence, including information from a telephone conversation the Russian authorities had intercepted between Tamerlan and his mother in which they discussed jihad, the Times said.
"They found that the Russians did not provide all the information that they had on him back then, and based on everything that was available the FBI did all that it could," the Times quoted a senior American official briefed on the review as saying.
Dzhokhar Tsarnaev's trial begins in November.
The one-time student has pleaded not guilty to 30 federal charges related to the bombings, including 17 serious charges that can carry sentences of death or life in prison.
These charges include using a weapon of mass destruction resulting in death, as well as conspiracy and bombing of a place of public use resulting in death, and carjacking.
He is also charged in connection with the fatal shooting of a campus police officer at the Massachusetts Institute of Technology during the brothers' wild overnight getaway attempt.
