The woman said she was asleep at her family home in Rajanpur, in the country’s central Punjab province, when the attack happened.
She reported the crime to the local panchayat, a tribal court that operates outside the official justice system in remote areas of the country, but was told she had intentionally seduced her attacker.
The panchayat, which included the alleged rapist’s father, then found her guilty of adultery and declared her a Kari, or adulteress, the Express Tribune reports.
The council decided no action needed to be taken against the alleged rapist.
The following day the woman and her father went to the police, who have now launched an official investigation.
An arrest warrant has now been issued for the members of the tribal council, and the woman taken to a refuge away from the village.
Women declared Kari are often executed by their own family in so-called honour killings to restore their reputation.
Another warrant has also been issued for the alleged rapist, local media reports.