After recovering from stab wounds recently suffered in prison, "The Minister of Justice and Correctional Services, Ronald Lamola, has placed offender Janus Walus on parole under strict conditions with effect from Wednesday, 07 December 2022," the government said in a statement.
A spokesman confirmed that this meant Walus had been released, in line with a decision by the Constitutional Court.
The parole decision sparked fierce protests from the ruling African National Congress (ANC) and its ally in the struggle against apartheid, the South African Communist Party (SACP).
Hani, a hugely popular figure and fierce opponent of white rule, was killed in his driveway just as negotiations to end apartheid were entering their final phase.
The murder almost plunged South Africa into a race war.
Walus was quickly arrested after the killing and handed the death sentence -- a punishment that was commuted to life imprisonment after the death penalty was abolished in post-apartheid South Africa.
The Constitutional Court on November 21 granted Walus parole and gave the prison service 10 days in which to release him.