The police are trying to trace the mechanic’s wife, the girl’s stepmother, who left him a few years ago out of disgust.

The woman had married the mechanic in 2004.

After the mechanic, an excessive drinker, divorced his first wife, a Cambodian, his daughter stayed at a home before he regained her custody. The mechanic’s father arranged the second marriage, apparently in the hope that it would reform him. He remarried in 2004 but she left him within two months, police said.

“We suspect he had tried to force this woman into prostitution and this why she left. Some of the things the girl has said in her statement back up our suspicions. The woman might prove a strong witness as she might be aware of the treatment meted out by her husband to her stepdaughter. We are trying to find her,” senior inspector Purushottam Gawande of the Charkop police said.

He said they are following a lead that two other men might have been involved in the rape of the girl, apart from the two arrested friends of the mechanic.