Police sources said that the minor, a Class 12 student, was arrested on October 13 from Thoubal district.
He was remanded in the observation home, run by the social welfare department of the Manipur government.
He allegedly committed suicide by hanging himself from a ceiling fan in the home. L. Manojkumar, Superintendent of the home, said the home was not responsible for the incident.
However, Yumkhaibam Lembi, the deceased's mother, said: "My son was pressurised to confess to his involvement in the death of the girl. He was innocent.
"He had told the court that he was tortured inside the home to make him confess to the crime he did not commit," she said.
There were protests at the home by the minor's relatives. Police was rushed there to maintain law and order.
Security was also beefed up in the localities where the minor and the girl lived, fearing lawlessness.
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)