Mlungisi Sisulu, son of Max and Elinor Sisulu, died in London early on Thursday morning, the Department of Foreign Affairs said.
Departmental spokesperson Ronnie Mamoepa said Mlungisi, who was in his late 30s, died from a ”suspected illness” at 3am on Thursday.
Sisulu, first secretary of the South African Embassy in Khartoum, Sudan, was on a visit to London at the time of his death.
Minister of Foreign Affairs Dr Nkosazana Dlamini Zuma extended condolences to the family of Sisulu.
”Death has once more robbed the government, the people of our country and indeed the Department of Foreign Affairs, of the distinguished services of one of our rising diplomats, Mlungisi Sisulu,” she said.
”Mlungisi served the Department of Foreign Affairs, and indeed the country, with diligence, professionalism, loyalty and great dedication.”
Mlungisi, who joined the Department of Foreign Affairs in 1999, previously served as the first secretary in the South African embassy in Prague, Czech Republic.
A senior official has been dispatched by the Department of Foreign Affairs to accompany members of the Sisulu family, led by Max Sisulu, to London to finalise arrangements for the return of the body. — Sapa