The New York police department is facing renewed questions over the conduct of its personnel after a man alleged he was viciously assaulted without provocation by a group of uniformed officers. Santiago Hernandez, 23, claims that he was kicked, punched, and zapped with pepper spray by up to six officers on 157th Street in the Bronx on 18 August. A video of his arrest captured by a nearby security camera and published by the local TV channel ABC 7 shows the police initially frisking him, then handcuffing him, and finally piling on top of Hernandez as he lay on the sidewalk while apparently hitting him with batons.

“They was taking turns on me. One kicks me, he steps back. Another one comes to punch me and he steps back. And another one comes and grabs my arm and hits me like 10 times with the baton. Another one comes and pepper sprayed me … they were taking turns like a gang,” he told ABC 7.

The new allegations, that are being investigated by the NYPD’s internal affairs section, come at a difficult time for the force and its high-profile commissioner Bill Bratton.

A grand jury has been called to decide whether to bring charges against an NYPD officer involved in the attempted arrest in Staten Island of Eric Garner for selling loose cigarettes.

Garner, 43, died on 17 July as he was put in a chokehold – a procedure that has been banned.