The incident took place in a village under the Dharmapuri police station in Dhar district of Madhya Pradesh.
Pankaj Jain, a member of the district childline, said a panchayat was convened in the village after it was found that the 15-year-old had allegedly eloped with her brother-in-law.
According to locals, the panchayat was called at the behest of the minor girl's elder sister, who had alleged that she was having an affair with her husband.
The authorities received the information that the family members of the minor, on directions from the panchayat, had fixed a deal to sell off the girl to a 35-year-old man from Mannawar tehsil in the district, Jain said.
Local police confirmed the incident and said a case would be registered after investigations are conducted.
Preliminary investigations suggest that the parents of the minor had struck a deal with the 35-year-old Mannawar resident for Rs 1.55 lakh, of which Rs 5,000 has already been paid to the head of the caste panchayat. Another Rs 5,000 has been kept aside for a community feast, police said.
The 15-year-old girl's parents allegedly received some of the amount, but the matter is being probed, police said.