The International Criminal Court’s chief prosecutor, Fatou Bensouda, on Tuesday arrived in Kinshasa to begin probe into allegations of deadly violence.
The ICC said, the visit follows requests into crimes against humanity in this Central African nation.
Bensouda is scheduled to meet with government officials and judicial institutions, and address a press conference on Thursday.
In January, an European Parliament resolution urged the ICC and the UN to investigate allegations of crimes against humanity in the Kasai region.
In March, the Congolese citizen movement also asked the ICC to investigate repression of peaceful demonstrations.
A total of 16 people have been killed since December last year in the repression of three marches by a collective of the Catholic Church in the country.
The protesters were asking President Joseph Kabila to publicly declare that he would leave power.
Elections are scheduled for December 23 in the DRC for the departure of President Kabila, who is still in power despite his second and final term ending on 20 December, 2016.
The opposition was able to gather at a meeting a week ago for the first time since September 2016.
On Tuesday, several activists of the pro-democracy movement Fight for Change were arrested as they wanted to demonstrate in eastern Goma. Two leaders, Fred Bauma and Rebecca Kavugho, were later released.