Two UN investigators killed in March likely died at the hands of Congolese militia members, a UN inquiry found, adding that further investigation will be required to "fully ascertain the identity" of those involved.
Michael Sharp, an American, and Zaida Catalan, a Swedish-Chilean dual national, were found murdered in March in the Democratic Republic of Congo while on a UN mission investigating violence and mass graves in the country's restive Kasai province.
"A group of Congolese, likely militia members from the Kasai Central province, was responsible," read the board's executive summary, obtained Wednesday by AFP. "There was a reasonable likelihood that the killings were committed after consultation with other local tribal actors."
But UN Secretary-General Antonio Guterres emphasized in a letter dated August 15 and sent to the Security Council that the board said "further investigations and judicial processes would be required to fully ascertain the identity, affiliations, and motives of the individuals involved in the killing of Mr. Sharp and Ms. Catalan."
After Sharp and Catalan disappeared on March 12 their bodies were found 16 days later, with Catalan's decapitated.
A report sent to the council in June called the murder a "premeditated setup" and that it may have included members of state security services.
Two men were put on trial for the murders of Sharp and Catalan and there have been arrests, but the group of experts said "other key suspects" have not been detained despite available evidence.
Speaking to journalists Wednesday, Guterres vowed that every possible step would be taken to ensure "the criminals would be punished."
A military tribunal in Kananga has given the go-ahead for all parties to go to the scene of the crime, a visit scheduled for August 21.
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. Some 1.4 million people have been displaced by the violence.