An FIR has been registered against unidentified persons with the Economic Offences Wing based on a complaint filed by the Rajya Sabha MP and its cyber cell is looking into the matter, Delhi Police PRO Madhur Verma said.
The official said the case was registered on the charges of "forgery for harming reputation, criminal intimidation and insulting a woman's modesty".
Ms Sasikala, who was expelled from the AIADMK in August last year, had earlier alleged she was slapped by a party leader in Chennai and was facing death threats.
The police said that websites have been asked to provide details of it.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.