The police officer who shot dead Michael Brown in the US town of Ferguson says he was pinned in his vehicle and struggling over his gun with the black teenager, a news report said.
Brown's death two months ago sparked ongoing protests, some violent, in the town near St Louis and shone a spotlight on police tactics in the United States and relations between US law enforcement and African Americans.
The white policeman, Darren Wilson, has told investigators that he feared for his life, The New York Times reported on Saturday, citing government officials briefed on the federal civil rights investigation into the fatal shooting of Brown, 18.
During the scuffle, Brown reached for the officer's gun, according to Wilson. The weapon was fired twice in the car, FBI forensics tests have revealed.
The first bullet hit Brown in the arm and the second bullet missed. Wilson also told authorities that Brown had punched and scratched him repeatedly, the Times reported.
The first public account of Wilson's testimony to investigators does not explain why, after he emerged from his vehicle, he fired at Brown multiple times.
It also contradicts some witness accounts which said Brown appeared to be surrendering with his arms held aloft. Police officers typically have wide latitude to use lethal force if they reasonably believe that they are in imminent danger.
The federal investigation into the August 9 shooting continues.