He had been appointed as mayor on 10 August and served in the position for just over a month.
A spokesperson confirmed to the media that the mayor had died. This was further confirmed by two more sources in his office. A statement was expected to be issued on Saturday night.
Matongo had earlier on Saturday accompanied President Cyril Ramaphosa in Soweto, to campaign for the ANC ahead of this year’s municipal elections.
Late on Saturday night, Ramaphosa said in a statement that the accident happened after the campaigning.
Ramaphosa said: “It is hard to comprehend this tragedy, given the vitality and passion with which Mayor Matongo interacted with me and residents of Soweto so shortly before his death.
“Nothing could prepare any of us for this sudden loss, which has deprived our nation’s economic centre of its second Executive Mayor in two months.
“Matongo has been taken from us at a time when he was totally immersed in improving conditions and creating opportunities for all the people of Johannesburg and stakeholders in the metropolitan economy. Like all of us, he was looking forward to the forthcoming election, and we saw in person today that he had put his heart and soul into mobilising the people of the city to make their voices heard on 1 November.”
Matongo had been elected unopposed as Joburg mayor, succeeding Geoff Makhubo, who died in July of Covid-19 complications.
He served as the MMC for Finance under Makhubo.
He had risen through the ranks, from serving as a member of the Soweto Student Congress and the Congress of South African Students before moving on to serve as the regional head of communications in the ANC for eight years.
He had also served as the chief of staff responsible for the overall running and functioning of the offices of the Gauteng MEC for the sport and economic development and agriculture departments.