Several US lawmakers have questioned the manner in which the FBI handled the information it had received from Russia about one of the Boston bombing suspects and the way he was allowed to walk free after questioning.

“As far as getting information in advance and not seeming to take proper action, this is the fifth case I’m aware of where the FBI has failed to stop someone who ultimately became a terrorist murderer,” Congressman Peter King told Fox News.

King and several other Congressmen and Senators are asking why the FBI did not follow the lead it had received from the Russians against Boston bombings suspect Tamerlan Tsarnaev, 26, who died last week in a shootout with police.

His brother and the second suspect — Dzhokar Tsarnev — was arrested last week after a massive manhunt.

“I have great regard for the FBI and for Director (Robert) Mueller, but this is the latest in a series of cases like this where the FBI is given information about someone as being potential terrorists, they look at them, and then they don’t take action,” said King, a member of both the Homeland Security and Intelligence committees.

“There are a lot of questions that had to be answered (by the FBI). This man was pointed out by a foreign Government to be dangerous. He was interviewed by the FBI once. What did they find out? What did they miss? Then he went to Russia and to Chechnya. Why wasn’t he interviewed when he came back, either at the airport when he was returning or later? And what happened in Chechnya that may have radicalised him?” Senator Chuck Schumer asked on the CNN.

Noting that there were things on his Website that indicated he had been radicalised, Schumer said certainly, when a foreign Government points out that something is wrong or something might be wrong, he ought to be interviewed again.

“While the FBI has done a very good job over the last 10 years, I certainly think there are questions that have to be answered,” Schumer added.

House Homeland security Chairman, Michael McCaul, also lashed out at the FBI on its handling of the suspect case.

“It is important enough to have a foreign Government tie him to extremism. I always give the FBI the benefit of the doubt. I’m sure they interviewed him. You can’t detain all lawful persons in the US... There were concerns about this individual, and yet, when he travels abroad and gets to a very dangerous part of the world, nothing seems to be done. Why is Chechnya important? I think the American people need to understand this. The Chechen rebels are some of the fiercest jihadist warriors out there,” McCaul told CNN.

“My understanding is Russian intelligence service contacted the FBI and said you have an individual that has potential ties to extremism. That he was interviewed by the FBI in 2011 and let go. And after that time is what’s very interesting is that the older brother travels back to Russia.

His father lives in the Chechen region. He spends six months there. He comes back,” McCaul said.

“One of the first things he does is puts up a YouTube Website throwing out a lot of jihadist rhetoric. Clearly, something happened in my judgment in that six-month timeframe.

He radicalised at some point in time. Where was that and how did that happen? I’m very concerned. That six months is very important. So, why is the FBI interview important?” he asked.

“Because if he was on the radar and they let him go, he’s on the Russians radar, why wasn’t a flag put on him, some sort of customs flag? I’ve done this before. You put a customs flag up on the individual coming in and out. And I’d like to know what intelligence Russia has on him as well. I would suspect that they may have monitored him when he was in Russia,” the Congressman said.

The FBI in 2011 interviewed Tsarnaev at the request of a foreign Government (now acknowledged by officials to be Russia) that suspected he might have ties to Chechen extremist groups with links to al-Qaeda.

“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,” it said in a statement.

The US investigative agents apparently let him out of their sights after not detecting any terrorist activity.