Mr Osei-Mensah, who also doubles as the Head of the Regional Security Council (REGSEC), was led to swear an oath before hearing began on Tuesday, July 6.
The committee led by Court of Appeal judge Justice George Kingsley Koomson is sitting to gather evidence and eye-witness accounts on the possible reasons that led to the unrest in Ejura on Tuesday, June 29.
The unrest resulted in the killing of two and injuring of four.
They have 10 days within which to present their report.
Having been constituted on Wednesday, June 30, the committee, also made up of Dr Vladimir Antwi Danso and Juliet Amoah as members, is expected to present its recommendation to the Minister of Interior by Friday, July 9.
The unrest in Dagombaline in Ejura was sparked by the death of social media activist Mohammed Iddrisu, popularly known on Facebook as Macho Kaaka.
By Emmanuel Kwame Amoh|3news.com|Ghana