Indrani Mukherjea was detained by suburban Khar police, DCP (Detection) Dhananjay Kulkarni said without elaborating.
"Cannot comment anything regarding her detention as the police are still probing the case," he said.
The case dates back to 2012 when Raigad police had found the remains of Indrani's sister, following which a murder case was registered against unidentified persons.
Indrani is being questioned in Khar police station.