The victim, who is 13 years old, was found to be pregnant during a medical check-up today, after which the police complaint was filed.
Police didn't disclose identity of the accused.
The victim, who is an orphan, was living with the accused's family in Vasco town.
As per the statement of the girl, the accused, who is married and has two children, raped her on four occasions in the last three months.
"We have arrested the man," a police spokesperson said.