Sona Comstar, part of the Rs 30,000 crore Sona Group, has issued a cease-and-desist letter to Rani Kapur, the mother of former Chairman Sunjay Kapur, who died in England in June.

According to the letter, Rani Kapur, who claimed majority shareholder status last week and claimed she was "coerced" into signing documents supporting her daughter-in-law, Priya Sachdev Kapur,'s, candidacy as a non-executive director, defamed the firm and caused it harm.

Rani Kapur and her advisers have not yet answered. Rani Kapur issued an e-mail last week demanding that Sona Comstar postpone its annual general meeting.