FBI agent in Boston bombings in clear over shooting of suspect's friend

Investigators have concluded an FBI agent should be cleared of wrongdoing over the fatal shooting of a Chechen immigrant while he was being questioned about his ties to one of the Boston Marathon bombing suspects, a US law enforcement official said.

The agent shot and killed 27-year-old Ibragim Todashev last May after Todashev suddenly attacked and injured the agent during an interrogation at his Orlando apartment, according to the FBI.

A review of the incident prepared by a team of investigators at the office of Orlando State Attorney Jeffrey Ashton recommended clearing the FBI agent, the official said. A separate unpublished FBI report, had also concluded the agent was justified in using deadly force.

Todashev was an acquaintance of Tamerlan Tsarnaev, one of two Chechen brothers who prosecutors say carried out the Boston bombing, which killed three people and injured more than 260.

He was shot and killed while being questioned about his suspected involvement in a triple murder in 2011 that law enforcement officials suspected was linked to him and Tsarnaev.

The FBI account has been questioned by Todashev's father, who has said his son was unarmed when he was shot.

A Muslim civil liberties group in the state of Florida, the Tampa-based branch of the Council on American-Islamic Relations, has called for a detailed review of the shooting.

US prosecutors could announce their decision not to bring charges against the FBI agent as soon as Tuesday, the same day Ashton is expected to announce the findings of his investigation.

Hassan Shibly, executive director of the Florida Council on American-Islamic Relations, expressed concern about the conclusions of the investigations.

"The Department of Justice's and the State Attorney's investigations relied on evidence gathered by the FBI and the only person who can contradict first hand their narrative is dead," Shibly said.