Police sub-inspector H B Dagade of the Ulhasnagar Central Police station told PTI that one of the accused named Sandeep Gaikwad, allegedly photographed the 18-year-old girl while she was bathing.
Later, he allegedly blackmailed her and raped her several times at different places for six months, the girl's complaint stated.
On June 2, 2015, the two married couples caught hold of the girl near the Chopda court beat her up and tore off her clothes, the complaint said.
According to the police official, the other three accused who beat up the girl are Madhukar Birhade, his wife and Sandeep Gaikwad's wife, who are all residents of a slum colony near the Chopda court.
However, nobody has been arrested so far, the police official said.