The FBI shot and killed Ibragim Todashev Tuesday night, an Orlando man being questioned regarding the Boston marathon bombings and a friend of suspected terrorists Tamerlan and Dzhokhar Tsarnaev, ABC News reported.

Todashev was being questioned by the FBI about his relationship with the brothers/suspects, the alleged Boston bombers who carried out a terrorist attack on April 15 in Boston. A law enforcement source said that Todashev was shot and killed by an agent who felt his life was being threatened.

"There was some sort of aggressive movement that led the FBI agent to believe he was under threat and he opened fire," the source said.

The FBI confirmed the death in a statement. They said that the FBI agent was receiving care but did not offer further details on the matter.

"We are currently responding to a shooting incident involving an FBI special agent," FBI spokesman Dave Couvertier said , according to NBC. "The agent encountered the suspect while conducting official duties. The suspect is deceased."

Todashev was believed to have lived in Boston at one point. A source said that the killing came as a surprise since the 27-year-old has been cooperative thus far in interview proceedings. However, he alledgegly attacked the official at one point and the situation escalated. A friend of Todashev's, Khusn Taramiv, told WESH-TV in Orlando that he was also interviewed by the FBI.

"And they said they need him for a little more, for a couple more hours, and I left, and they told me they're going to bring him back. They never brought him back," Taramiv said.

Taramiv also added that Todashev had concerns about his safety,,saying Todashev "felt he would be "shot in the head."

The investigation to the Boston bombings may now be hindered with another potential source of information now dead.  Tamerlan and Dzhokhar are accused of setting off a pair of bombs near the finish line of the Boston Marathon in April that resulted in three being killed and injuring more than 260 others.

Tamerlan was killed in a shootout with police days following the explosion, while Dzhokhar was later captured.

Tags: boston bombing tamerlan tsarnaev dzhokhar tsarnaev