After the 12-year-old did not reach home on Wednesday, her parents filed a missing complaint.
A 10-year-old girl was detained in Jaipur on Saturday for allegedly killing a classmate, who had come to her place, after the two got into an argument over snatching a pen, police said.
The parents of the accused, who were not at home at the time of the incident, have been arrested for allegedly destroying evidence, they said.
The accused had snatched a pen from her classmate. On Wednesday, the 12-year-old went to the house of the accused after school and the two got into an argument over the issue, senior police officer Braj Mohan Kaviya said.
During the argument, the accused attacked the girl with an iron rod. The girl sustained injuries on her head, ribs and stomach, which led to her death, he said.
According to Mr Kaviya, after the parents of the accused got home, she narrated the entire story to her mother. To destroy evidence, the two tied the victim's body to a rock and threw it in a pond.
Later, the mother of the accused informed her husband. Finally, they fished out the body from the pond and dumped it in an open ground, the SHO said.
After the 12-year-old did not reach home on Wednesday, her parents filed a missing complaint. Her body was recovered on Thursday, Mr Kaviya said.
Further probe is on, he said.