As per the complaint lodged by the man's former wife on December 8, the minor was raped continuously for six months by his father, who used to force her to consume alcohol before committing the crime.
The incidence came to light when the child was taken to a psychiatrist by mother following some changes in her behaviour, police said.
The child told the doctor that she was sexually abused by her father and some others.
The minor and her younger sister are now at Juvenile Home at nearby Kakkanad, police sources said.
A case was registered by the police under the Protection of Children against Sexual Offence Act and Section 328 of IPC (giving liquor to a minor).