However, the case of another minor boy, also allegedly involved in the offence, has been referred to juvenile court.
The accused and the girl's family are residents of Naupada area in Thane city.
According to prosecution, Ramzan alias Baba Rukhmuddin Shaikh (22 years old in 2009) wanted to marry the 18-year-old daughter of a tempo driver, but her family was against it.
He then allegedly started harassing the girl and her family members.
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They allegedly attacked the girl's family members with a chopper and other weapons, injuring them.
The three accused then took the girl with them to a lonely place and allegedly raped her repeatedly.
Among the girl's family members injured in the attack were her father and her 80-year-old grandfather, the prosecution told the court.
Appearing for the accused, advocate C D Deshpande argued in the court that they had no connection with the incident and had been falsely accused of the crime. Hence, the court needs to set them free, the counsel said.
After hearing both the sides, Thane Additional Sessions Judge V V Virkar concluded that the prosecution had miserably failed to prove the charges against the accused.