A man has been arrested for allegedly sexually assaulting his eight-year-old step daughter in a village near Ponkunnam in the district, police said on Thursday.
A case was registered against the mother of the child for not informing police about the assault even after coming to know about it.
The issue came to light when the girl studying in third standard shared her ordeal with her friends.
They informed her class teacher and the school authorities after counseling the child lodged a complaint with the police.
When the mother was informed about the assault, she allegedly told the child not to tell anyone about the incident, police said.
The accused has been charged under various sections of Protection of Children from Sexual Offences (POCSO) Act.