A panel probing the circumstances leading to former Chief Minister J. Jayalalithaa’s death Thursday said it has summoned Deputy Chief Minister O. Panneerselvam to appear before it on December 20.

Mr. Panneerselvam, who had held the portfolios of late Jayalalithaa during her hospitalisation in 2016, will appear after Health Minister C. Vijayabaskar who has been directed to be present on December 18 before the Justice A. Arumughaswamy Commission of Inquiry.

Senior AIADMK leader C. Ponnaiyan and police officer Sudhakar, who was part of Jayalalithaa’s security team, have also been summoned to appear on December 18 and 20 respectively, commission sources told PTI.

Mr. Panneerselvam had demanded a probe into the circumstances surrounding Jayalalithaa’s death after he revolted last year against V.K. Sasikala, confidante of Jayalalithaa.

Sasikala is now serving a prison sentence in a Bengaluru jail in the disproportionate assets case.

In his first public comments on February 8 last year on Jayalalithaa’s hospitalisation, Mr. Panneerselvam, then Chief Minister, had said he could not meet her even once during her 75-day hospitalisation.

In September 2017, the state government constituted the panel under the Commissions of Inquiry Act, 1952.

The panel’s terms of reference was to inquire into the circumstances leading to Jayalalithaa’s hospitalisation on September 22, 2016, and treatment provided till her death on December 5, 2016.

Following Jayalalithaa’s death, suspicion on the circumstances leading to her death was raised by several people, including Mr. Panneerselvam and his followers.

After unification of the factions led by Chief Minister K. Palaniswami and Mr. Panneerselvam in August 2017, the government notified constituting the panel.

The probe was a key precondition put forth by Mr. Panneerselvam for the merger.