WASHINGTON — A man who was killed in Orlando, Fla., last week while being questioned by an F.B.I. agent about his relationship with Tamerlan Tsarnaev, one of the Boston Marathon bombing suspects, had knocked the agent to the ground with a table and ran at him with a metal pole before being shot, according to a senior law enforcement official briefed on the matter.

The official’s account of the shooting, the most detailed to date, came several hours after the man’s Chechen father claimed at a news conference in Moscow on Thursday that his son, Ibragim Todashev, was unarmed when he was killed on May 22. The father, Abdulbaki Todashev, displayed photographs of his son’s bullet-ridden body and demanded that the United States government explain how he was killed.

On the day of the shooting, federal law enforcement officials provided differing accounts of the episode, initially saying Mr. Todashev had a knife. Later they said Mr. Todashev had “exploded” at the agent and might have had a pipe or might not have had anything in his hands.

The shooting occurred after an F.B.I. agent from Boston and two detectives from the Massachusetts State Police had been interviewing Mr. Todashev for several hours about his possible involvement in a triple homicide in Waltham, Mass., in 2011, according to the law enforcement official, who spoke on the condition of anonymity because the investigation was continuing.