A white South African farmer and his two employees accused of shooting dead two black women and feeding their bodies to pigs have gone on trial for their murders.

Maria Makgato, 45, and Lucia Ndlovu, 34, were allegedly looking for food on the farm near Polokwane in South Africa's northern Limpopo province last year when they were killed.

Their bodies were then alleged to have been given to pigs in an apparent attempt to dispose of the evidence.

Farm owner Zachariah Johannes Olivier, 60, and his employees Adrian de Wet, 19, and William Musora, 50, are yet to enter a plea and remain behind bars.

The case has sparked outrage across South Africa, exacerbating racial tensions in the country.