Congo's minister for human rights says investigators may have found the remains of the four Congolese men who accompanied two U.N. experts who were killed in the central Kasai last year.

Marie-Ange Mushobekwa said Monday that medical examiners must still verify the identities of the bodies found April 24 in the village of Moyo Musuila, north of Kananga.

American Michael Sharp and Swedish-Chilean national Zaida Catalan disappeared March 12, 2017, while investigating possible violations of U.N. sanctions against Congo. Their bodies were found in shallow graves 15 days later.

Investigations into their deaths have been ongoing. The government has said they were accompanied by an interpreter, a guide and two motorcycle drivers.

Mushobekwa says 19 people have been arrested in connection with the killings in the Kasai region.