The Internal Affairs Bureau at the New York Police Department is looking into an assertion that officers unlawfully entered and searched a Brooklyn apartment belonging to a man who had accused officers of assaulting him in his building, police officials said Thursday.

Parts of both instances were recorded by surveillance cameras set up by the man, Jabbar Campbell, a data recovery specialist who runs a recording studio in his home.

In the first episode, in January, Mr. Campbell said, officers kicked and punched him in the ground-floor hallway of the building in the Crown Heights neighborhood, bruising his face and cutting his lip. The recorded images did not show contact between Mr. Campbell and the officers, but a camera aimed at the front stoop showed a sergeant turning the lens to a wall before entering the building that night.