Sizani died on Sunday after being hospitalised for a short time at 1 Military Hospital, spokesman Dumisa Ntuli said in a statement.
“Comrade Zweli was not just an ordinary cadre, but he was a man of great integrity and political vision.
“He trained and educated many cadres through his teachings and lecturing in the ANC political school,” Ntuli said.
He said Sizani was a former Umkhonto we Sizwe combatant and a stalwart of the June 1976 uprising.
The African National Congress in Gauteng sent its condolences to Sizani’s family and friends.
“We salute with the ANC banner. His memories and love for politics will be with us forever,” Ntuli said.
“He will be long remembered for his teachings, wit, humour, smile and kindness.”