A formal inquiry has been initiated into alleged police excesses in the compound of the district school inspector's office in Kasba.
Officers at the Kolkata Police headquarters said all the allegations and electronic evidence that emerged were being probed.
An officer seen kicking a protestor in a video has been identified as a sub-inspector of the Kasba police station.
Sources said the sub-inspector was questioned by senior officers on Thursday as part of the inquiry.
He is said to have cited sudden lawlessness in the compound and an attack on the police as the trigger for action that has heaped shame on the city's police force.
Sources said his role was being probed by an officer of the rank of deputy commissioner. What led to the incident is also a part of the probe, the sources said.
Deputy commissioner (south suburban division) Bidisha Kalita did not comment on her force's conduct or the progress of the probe.
Text messages sent to the sub-inspector seeking his version of the incident did not yield a result.
Many civilians across Bengal complained why "no action" was taken against the officer.
"The police do not receive training to handle a law and order situation by kicks. It is an individual's action and should not be associated with the entire force. Anyway, being kicked by a man in uniform is unacceptable and deserves punishment," said a former cop who retired as an assistant commissioner of Kolkata Police.
Kolkata Police on Thursday circulated multiple video footage through their social media handles, showing some of the incidents in the office compound on Wednesday.
One of the videos showed a protester screaming: "petrol diye jaliye debo (will burn down the place with petrol)." Many men and women scale barricades and storm the office compound, allegedly following this man's call.
The other videos show the police being heckled before the lathicharge begins.
Kolkata Police issued a clarification through its social media handles: "Some unscrupulous individuals are spreading misinformation that videos posted by Kolkata Police do not pertain to yesterday's incident.
Clarification: the clips were merged only for representation in a single video. Separate clips are below, including one showing a protestor calling to 'burn down the place with petrol.' Faced with such unrelenting aggressive behaviour, Kolkata Police was compelled to use mild force in self-defense and disperse the unruly mob."
Police commissioner Manoj Verma had appealed to all the protesting teachers and non-teachers not to take the law into their own hands even if they were aggrieved.