A South African court has cleared the way for the release of a Polish immigrant jailed for killing a prominent anti-apartheid leader.

Janusz Walus had been sentenced to life for the 1993 assassination of Chris Hani, leader of the military wing of the African National Congress, now the country's ruling party.

He was granted parole in March after nearly 23 years in jail, a decision appealed by the justice minister. A court in Pretoria on Thursday dismissed the appeal.

The killing of Hani stirred fears of all-out racial conflict, but Nelson Mandela calmed the situation. He won South Africa's first all-race elections in 1994, making him the country's first black president.

Hani's widow and some ruling party political activists opposed Walus' release.