A 15-year-old in the Maldives whose father is accused of repeatedly raping her and killing the resulting baby risks being flogged for "fornication" with another man under the nation's strict Islamic law, a police source says.

In the course of inquiries into the rape case, investigators say they unearthed evidence of the girl having had consensual sex with another man, which is an offence in the Indian Ocean holiday destination, the source said.

Women, including minors, having consensual sex outside marriage can be charged in the Maldives, where convicts can be publicly flogged. Minors receive the punishment when they reach 18, the age of majority.

The child's stepfather is accused by police of repeatedly raping the girl and fathering a child by her which he subsequently murdered. The girl's mother has been charged with helping dispose of the infant's body, police said.

"We completed the investigation (into the murder of the infant) and gave a report to the prosecutor-general's office," Maldivian police spokesman Hassan Haneef told AFP by telephone.