"We have arrested Puja Singh from Rashbehari area of south Kolkata in the evening. She was alone. We have brought her to the LakeTown police station," officer-in-charge of the LakeTown police station Ashok Sen told PTI.
The incident came to light on Wednesday after a CCTV footage showed the tutor mercilessly beating and torturing the kid.
The complaint lodged by the kid's family said the tutor, who was appointed just a few days back, had apologised and requested the kid's family not to inform the police.
But the family registered the police complaint after her husband came and threatened them not to lodge a complaint.
The incident was condemned by people cutting across political lines.
After the incident created a big furore, Singh went underground.
I-T laws that complicate your life
PHOTOS: Indian Army Chief honours fallen Kargil war heroes
Telangana bus crash: 11 students battle for life
Bengaluru rape case: Police did not follow SOP
UPSC aspirants clash with police, burn vehicles in North Delhi