This is not the first dubious appointment of Rwandan generals to major UN peacekeeping operations.

The United Nations has hired a Rwandan general to head a peacekeeping force in Darfur, despite his previous role as army chief of staff at the height of a deadly, Rwandan-backed insurgency in the Democratic Republic of Congo (DRC).

On Monday the United Nations and the African Union jointly announced that Rwandan Lieutenant General Frank Mushyo Kamanzi had been appointed force commander of UNAMID, a hybrid mission that provides security and humanitarian assistance in war torn Sudan.

The decision was taken despite General Kamanzi having served as one of the most senior military figures in Rwanda when the country supplied troops and weapons to a brutal militia in eastern Congo.

General Kamanzi was named army chief of staff in July 2012, just as Rwanda stepped up efforts to recruit soldiers, including children, and provide arms, ammunition and fighters for the M23, which was eventually routed by a UN intervention brigade.

Kamanzi was responsible for ‘command, control and management’ of Rwandan army services when M23 militia members were accused of the worst atrocities. At the time, M23 members slaughtered and raped Congolese civilians, and pillaged a string of communities in the DRC, according to Human Rights Watch and UN staff.

One of the militia’s warlords, Bosco Ntaganda, is now facing war crimes charges at the International Criminal Court.

In November 2012, the UN’s Group of Experts concluded that “Rwandan officials exercised overall command and strategic planning for M23.” Their report said Rwanda clearly violated the arms embargo and sanctions regime.

Despite these findings and General Kamanzi’s senior position during that period, the UN Department of Peacekeeping Operations (DPKO) said Friday he was properly screened and the UN did not have any specific information on him breaking international or humanitarian law.

“In line with the 2012 policy on Human Rights screening of UN personnel for senior appointments, the UN screened Lt Gen Mushyo Frank Kamanzi, the recommended candidate for the post of Force Commander for UNAMID, against available information from throughout the UN system” a UN peacekeeping official said.

“In the absence of specific information on Lt Gen Kamanzi’s involvement in violations of international human rights or humanitarian law, DPKO recommended the candidate for appointment. As per standard practice, if anyone has further information, we ask them to share it with the UN,” the official added.

DPKO relies in part on the UN Office of the High Commissioner for Human Rights (OHCHR) to conduct its screening for candidates.

Requests for a comment from the OHCHR this week went unanswered.

This is not the first dubious appointment of Rwandan generals to major UN peacekeeping operations.

From 2009 until 2013, Rwandan General Patrick Nyamvumba served as UNAMID force commander, despite evidence gathered at a UN tribunal that he headed a death squad targeting Hutu civilians during the genocide.

“Nyamvumba should have been charged with war crimes,” a former investigator with the International Criminal Tribunal for Rwanda (ICTR) told this journalist.

“Many people gave testimony against him. We had enough evidence to indict him 25 times over.”

“We were told to stop our investigations,” he said. “The United Nations and the ICTR were all about politics,” he lamented.

Nyamvumba ran the notorious Training Wing during the genocide and reported directly to Paul Kagame, head of the Rwandan Patriotic Front (RPA) and now president.

The ICTR investigator called Kagame’s army ‘highly disciplined.’

“Nothing was done by the RPA or by any soldier that was not approved by ‘number 1,’” he said, referring to the president.

“Kagame is ready to kill any Hutu. But anyone else who gets in his way or bothers him will disappear,” said the former investigator, who worked on major ICTR cases prosecuting Hutu génocidaires and for the Special Investigations Unit that probed RPA crimes.

Another Rwandan general hired to head a UN force in Mali, has also been linked to war crimes committed against civilians.

Former colleagues said Major General Jean Bosco Kazura, who served as force commander of the UN stabilization mission MINUSMA until December 2014, was deputy commander of Nyamvumba’s death squad that operated in the prefectures of Byumba and Kibungo during the genocide in areas cleared of former Rwandan Hutu army forces.

Under their supervision, thousands of Hutu men, women and children were rounded up and murdered, some dumped in mass graves and others brought to Akagera National Park where they were burned and incinerated, according to testimony from former Tutsi officers.

The officers said that after the genocide, Generals Nyamvumba and Kazura also oversaw the transport of Hutu male recruits from all areas of Rwanda to killing grounds near the Gabiro training barracks and in other areas of Akagera Park, which were off limits to NGOs and UN personnel.

In 2008, UN peacekeeping came under fire for renewing the contract of Lieutenant General Emmanuel Karenzi Karake as deputy commander of UNAMID, months after he’d been indicted by Spain in a case of universal jurisdiction. The Spanish court charged Karake with war crimes and genocide committed in Rwanda and the DRC when he headed Kagame’s Directorate of Military Intelligence from 1994 until 1997.