Kenyan envoy to South Sudan, Chris Karumba Mburu, died at his residence in Juba on Sunday night.
The Ministry of Foreign Affairs on Monday said the cause of death was yet to be established.
The former director of External Intelligence at the National Intelligence Service (NIS) is said to have collapsed and died at his Juba home on Sunday night.
The diplomat was nominated by President Uhuru Kenyatta in July 2018 in changes affecting the diplomatic service.
Ambassador Mburu accompanied South Sudan President Salva Kiir on Tuesday, February 11, for the State Funeral of retired President Daniel arap Moi at the Nyayo Sports Complex in Nairobi.
