Police said Muthupandi consumed poison in his house on Saturday night and died at local government hospital today without responding to treatment.
Local Police had initially charged Muthupandi with raping his daughter and sexually abusing her repeatedly and arrested him in October last year.
However, the CB-CID, which took over the investigation after the matter was taken to the High Court, dropped his name as his daughter deposed before a magistrate court that she had lodged the complaint against him due to pressure from police.
Muthpandi, his son and a few others were arrested in connection with the case.