The parliamentary commission, which will be headed by deputy Alisher Sabirov, was set up after protests erupted calling for the resignation of Prime Minister Feliks Kulov.
Legislator Tynychbek Akmatbaev was killed while investigating complaints about conditions at the prison. He was the third deputy of the Kyrgyz parliament to be killed this year.
The commission should complete its investigation by 15 November. Parliamentary speaker Omurbek Tekebaev told deputies at the 25 October session that the commission will not consider the matter of Kulov's resignation, akipress.org reported. He dismissed the calls for Kulov to step down as "a proposal from the street."
Neither Kulov nor President Kurmanbek Bakiev attended the parliamentary session.