Karisma has separated from Sunjay for over five years and is fighting a legal battle for divorce and custody of their two children - Samaira and Kiaan.
She had filed the case against Sunjay and his mother, Rani, who holds the family finances, earlier this week, a senior police officer said.
Based on the statement of the Bollywood star, Khar Police registered an FIR yesterday under IPC section 498-A (husband or relative of the husband's woman subjecting her to cruelty, section 34 (common intention), he said.
They then filed a fresh divorce application. The case is currently pending in Bandra family court.
Karisma could not be immediately reached out for comment.