Jayalalithaa death probe commission on Friday issued summons to Sasikala and Apollo Chairman Pratap Reddy.
Commission of Inquiry headed by Justice A. Arumughaswamy sent a letter to Sasikala asking her to file documents and evidence regarding the death of former Chief Minister Jayalalithaa to the commission within 15 days.
The state government has set up the panel headed by Justice A Arumughaswamy, a former Madras High Court judge, to probe the death of Jayalalithaa on December 6, 2016 at a private hospital in Chennai.
Earlier, Apollo's top hospital official had said that the late Tamil Nadu Chief Minister J Jayalalithaa was brought to Apollo Hospital in a 'breathless state' on September 22 last year and those she approved were beside her during her treatment there.
The AIADMK supremo spent 75 days in the hospital before breathing her last on December 5 last year.