The probe was a key precondition put forth by the Panneerselvam panel for the merger.
The Justice A Arumughaswamy Commission of Inquiry, probing the circumstances leading to former Chief Minister J Jayalalithaa's death, has completed examining 50 witnesses, including seven who had petitioned it.
Constituted by the Tamil Nadu government last year, following suspicions on her death, the one man panel has examined 43 persons as its witnesses so far. Also, seven persons who had petitioned the commission including DMK's P Saravanan, seeking the nod to depose were also examined, Commission sources told PTI.
The Commission, meanwhile, has issued summons to senior State official A Ramalingam (a former secretary of Jayalalithaa), SS Poongundran (aide of Jayalalithaa) and J Deepak (Jayalalithaa's nephew).
They have been summoned to appear on June 2 for cross examination by the late chief minister's aide VK Sasikala's counsel.
Also, assistant to VK Sasikala, KT Karthikeyan has been directed to appear on the same day for re-examination.
The editor of AIADMK mouthpiece "Namadhu Puratchi Thalaivi Amma," Marudhu Alaguraj, and son of late political commentator and actor, Cho S Ramaswamy, (a friend and well wisher of Jayalalithaa) R Sriram have been summoned to appear for examination on June 4.
So far over a dozen doctors, retired and serving government officials and police officers have been examined by the commission.
Last November, Madurai based DMK functionary P Saravanan, who had submitted a petition, was the first to be examined as a witness by the panel based on his affidavit. P Saravanan had said he brought to the panel's notice alleged discrepancies in press releases and the final discharge summary of the hospital where J Jayalalithaa received treatment.
In September 2017, the Tamil Nadu government constituted the panel under the Commissions of Inquiry Act, 1952. The panel's terms of reference was to inquire into the circumstances and situation leading to the hospitalisation of Jayalalithaa on September 22, 2016, and treatment provided till her demise on December five 2017.
The Commission had invited all those having "personal knowledge and direct acquaintance" in the matter to furnish information to it till date.
Following Jayalalithaa's death, suspicion on the circumstances leading to her demise was raised by several persons, including the present Deputy Chief Minister O Panneerselvam and his followers.
Then a rebel party leader, O Panneerselvam and his followers had demanded a probe into her death, either a judicial inquiry or a CBI probe. After unification of the factions led by Chief Minister K Palaniswami and O Panneerselvam, the government notified constituting the panel.
The probe was a key precondition put forth by the Panneerselvam panel for the merger. DMK President MK Stalin had batted for a CBI probe and also raised the issue during campaigning for the RK Nagar bypoll in April, which was subsequently cancelled.