Senior Police Inspector N S Bangale of Vartak Nagar police station here said that the complaint has been filed by Sarnaik's son Purvesh, who is the secretary of Yuva Sena, the youth wing of Shiv Sena.
According to Purvesh, a woman who identified herself as Mary Louis, a resident of Australia, befriended him on the Facebook and expressed desire to work for Yuva Sena.
When he met her at a hotel in Mumbai, she demanded Rs one crore from him, threatening to defame him and his family ahead of the coming Assembly elections in Maharashtra if he did not pay up.
An offence has been registered under sections 385 (extortion), section 503 (criminal intimidation) and other relevant sections of the Indian Penal Code. No arrest has been made yet.