A white South African farm worker accused of killing two black women says he was forced to feed their bodies to pigs, according to lawyers.

Adrian de Wet is one of three men facing murder charges after Maria Makgato, 45, and Lucia Ndlovu, 34, were killed while allegedly looking for food on a farm near Polokwane in South Africa's northern Limpopo province last year.

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

Mr De Wet, 20, turned state witness when the trial started on Monday and says farm owner Zachariah Johannes Olivier shot and killed the two women.

Ms Makgato and Ms Ndlovu were searching for soon-to-expire dairy products which had been left for pigs when they were killed.

Mr De Wet, a supervisor on the farm, will testify that he was under duress when he was forced to throw their bodies into the pig enclosure, according to both the prosecution and his lawyer.

If the court accepts his testimony, all charges against him will be dropped.

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

Such tension is especially rife in rural areas, despite the end of the racist system of apartheid more than 30 years ago. Most private farmland remains in the hands of the white minority, while most farm workers are black and poorly paid, fuelling resentment among the black population, while many white farmers complain of high crime rates.

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William Musora, 50, another farm worker, is the third accused. He and Mr Olivier, 60, are yet to enter a plea and remain behind bars.

The three men also face charges of attempted murder for shooting at Ms Ndlovu's husband, who was with the women at the farm – as well as possession of an unlicensed firearm and obstructing justice for allegedly dumping the bodies in the pig enclosure in an attempt to conceal evidence.

Mr Musora, a Zimbabwean national, faces an additional charge under South Africa's Immigration Act over his status as an illegal immigrant.

The Limpopo High Court was packed with supporters and relatives of the victims ahead of proceedings. Also present was Mr Olivier's wife, who was seated in the front row of the public gallery and could be seen wiping away tears.

Members of opposition party Economic Freedom Fighters, which has previously called for the farm to be shut down, were also present in the courtroom.

The trial was postponed to next week. (BBC)