A commission of inquiry into the deadly post-election violence in Zimbabwe – which was set to be led by former president Kgalema Motlanthe – could have been illegally formed, according to a legal think tank. The investigation team was expected to look into the killing of six people following military intervention in the southern African nation's capital, Harare, two days after the election, an AP report said. The seven members include British lawyer Rodney Dixon, counsel for Kenya's government at the International Criminal Court as it tried to avoid charges against now President Uhuru Kenyatta related to post-2007 election violence.President Emmerson Mnangagwa said the commission, led by Motlanthe, should finish its work in three months.The killings shocked Zimbabwe after the peaceful July 30 election, the first after the fall of longtime leader Robert Mugabe in November. Many saw the vote as ushering in a new era but the sight of troops sweeping into Harare to disperse opposition protesters raised fears about the future and questions about who was in charge.Constitutional requirementsMnangagwa, a longtime confidant of Mugabe who was sworn in late last month with promises of reforms, said the commission would look into the violence, the reasons behind the military intervention and whether the force used by the military was appropriate, said the report. However, according to legal think tank Veritas, the commission, which was yet to begin its work, could have broken some of the country's constitutional requirements. The legal think tank said Mnangagwa violated section 110(6) of the Constitution by unilaterally picking the commissioners without involving Cabinet.Section 110(6) of the Constitution reads: "In the exercise of his or her functions, the president must act on the advice of Cabinet, except when he or she is acting in terms of subsection 2."Although section 110(6) of the Constitution allows the president to act without Cabinet advice when exercising functions under subsection (2) of the section, appointing commissions of inquiry is not one of those functions. "Under the Commissions of Inquiry Act, the president is never required to appoint one, and, hence, if he does, he must act on the advice of the Cabinet." Zimbabwe has been without a cabinet since August 26 when Mnangagwa took the oath of office following a protracted Constitutional Court application challenging his victory.Cabinet can only 'advise'The commission was expected to be sworn in after President Mnangagwa's return from the Forum for China-Africa Cooperation in Beijing.Mnangagwa has indicated that the appointments would be gazetted to give them effect in law."When the president purportedly appointed the commission there was no cabinet to advise him, and only on August 30 shortly before he left for China, did he appoint two vice presidents and by doing so formed a cabinet of three – himself and the vice presidents," Veritas stated.But, according to NewsDay, some legal experts have disagreed with the legal think tank, saying the president was legally allowed to form a commission as per section 210 of the Constitution.Midlands State University law lecturer Valentine Mutatu said the president was legally entitled to appoint the commission even without the involvement of Cabinet. Mutatu was quoted saying, "the conclusion that the President was legally obliged to get advice from Cabinet might not be legally correct".Another rights lawyer, Prayers Chitsa, has agreed that the president did not need Cabinet to set up a commission, adding that Cabinet was only allowed to give the president advice and he was not obliged to take it into account. * Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.