"Seven persons have been arrested in connection with the case, father of the girl is one among them, they are said to have committed the crime with a desire to unearth treasure in the fort, about 34 km from here, but did not find anything", Gulbarga SP Amit Singh told PTI.
He said "the girl's father appeared to be innocent initially, but his involvement was established during the course of investigation, so he has also been arrested."
Girl's father is a Pesh Imam at Firozabad mosque and hails from Bihar, he added.
The complaint regarding the missing child was registered on May 22, but her mutilated body was found near her house on May 26.
Meanwhile, one of the seven men allegedly involved in the crime died in police custody, following which five police officials including an inspector and two sub-inspectors have been suspended, he said.
The probe regarding death in custody has been handed over to the Criminal Investigation Department.
Officials said they are awaiting the postmortem report on the death that happened in custody, adding, there were no external injuries on the body.