Kinshasa - Parliament in the Democratic Republic of Congo has authorised the state prosecutor to probe alleged involvement by a former minister in violence rocking the Kasai region, a judicial source said on Tuesday."The nature of the facts and the gravity of the clues surrounding national deputy Clement Kanku justify the exercise of public action," chief prosecutor Flory Kabange Numbi said on state television."The National Assembly has just agreed to our request," he said, without specifying whether Kanku's parliamentary immunity from prosecution had been lifted.Until last month, Kanku served as minister of development in the government of President Joseph Kabila although his tenure only lasted six months. He remains an MP.Kabange said that the judicial investigation was "a process aimed at precisely identifying those who give the orders, the leaders, so that they face the full force of law."In less than a year, brutal violence in the five central Kasai provinces has claimed more than 3 000 lives, according to a tally by the Roman Catholic church, and displaced 1.3 million people."The general prosecutor of the republic is ... looking for those who are potentially pulling the strings in this serious and sinister matter," Kabange said.Last month, the country's public prosecutor also said he was investigating allegations that Kanku may have been linked to the March murders of two UN experts investigating mass graves. Incriminating phone call The violence erupted last September after the death in clashes of a tribal chieftain, known as the Kamwina Nsapu, who rebelled against the authority of Kabila's regime in Kinshasa and its local representatives.The killing sparked violence that has escalated, including gross violations of human rights such as extrajudicial killings, rapes, torture and the use of child soldiers.Kanku could be charged with "participation in an insurrectional movement", Kabange announced more than a month ago.The MP came under scrutiny after the publication on social media of a recorded phone call in which an alleged member of the Kamwina Nsapu militia supposedly briefed him on violence by the insurgents at Tshimbulu in Kasai-Central, where they killed a colonel and his guards.In March, two UN investigators, Michael Sharp, an American, and Zaida Catalan, with dual Swedish-Chilean nationality, were murdered while gathering evidence about mass graves, following ruthless onslaughts on villages by the militia.Last month, The New York Times said Catalan had a recording of Kanku holding a telephone conversation with one of the suspected leaders of massacres in Kasai.In the conversation, Kanku appeared to be discussing setting fire to a town as well as killing officials, the paper said. On Friday, the UN Human Rights Council decided to send a team of international experts to help probe the violence, but the resolution specified that they should pass on conclusions to DRC authorities, while "perpetrators of deplorable crimes" should be accountable to the national judiciary. Kanku was a minister in the government formed in Kinshasa from December 20, 2016 - the day Kabila refused to step down when his second and last constitutional mandate expired - until May 9, under a political deal reached last October between the regime and a minority opposition group.Kanku did not return to government in the reshuffle of May 9.