Shahbagh OC Abu Bakar Siddique denied the allegation and termed the incident a scuffle.
Photographer Jibon Ahmed said he went to the book fair to cover the event and was parking his motorbike near the Suharawardy Udyan gate.
“A policeman pulled me by my shirt collar and asked me harshly not to park there. I told him he could say that gently. He and some others then started beating me,” Jibon said.
“I contacted a colleague over phone with the help of a pedestrian. Senior officials of the police station came to the spot.”
The OC said: “We will take action against the policemen if they are found guilty.”
Some Shahbagh policemen had assaulted a reporter and a cameraperson of ATN News TV station on January 26 when they were covering a strike.