A seven-year-old girl from Tamil Nadu's Pudukottai district, who went missing on June 30, was found dead a day later.
Police sources say they suspect it to be a case of sexual assault.
A 25-year-old man, who was the family's neighbour, has been arrested.
The girl was playing near her house and went missing on Tuesday after which her family lodged a complaint with the police. Meanwhile, family members and neighbours were also frantically searching for the minor.
The girl's body was found near a water body in the district and her face bore numerous bruises.
The police suspect she was sexually assaulted and then murdered. Two people, including a 25-year-old youth, have been detained so far and an investigation is underway.
The autopsy report is awaited to know the cause of death.