Mandhira Kapur Smith, sister of late Sona Comstar Chairperson Sunjay Kapur, alleged that her mother was locked in a room and forced to sign documents after Sunjay's demise. "I was banging on the door. She was made to sign papers to give up everything," she said. "Sona is not just a company, it is part of our blood," Mandhira added.