The inquiry commission formed to investigate the incidents that of September 8 and 8 has sent a letter to then home minister Ramesh Lekhak, summoning him to record his statement.
The commission wrote to Lekhak on Tuesday, asking him to appear for questioning on Friday, said commission chair Gauri Bahadur Karki.
The commission has already recorded statements from most individuals involved in the incidents of September 8 and 9.
It is now preparing to record statements from Lekhak and then-prime minister KP Sharma Oli.
The commission is also preparing to issue a letter to Oli, formally summoning him to record his statement.