Authorities allege the victim, 43-year-old Nelson Chisale, was murdered by his former boss Mark Scott-Crossley and two former colleagues.
The trio face charges of murder, malicious damage to property and assault with intent to do grievous bodily harm.
A fourth man has turned state witness and been cleared of all charges.
Police recovered Mr Chisale’s skull, pieces of leg, a finger bone and his bloodied clothes more than a week after he was reported missing.
He’d reportedly been sacked for running a personal errand during work hours.
Court papers say he was returned to the safari park, about 400km north-east of Johannesburg, to collect personal belongings when he was attacked with knives, tied up with electoral wire and thrown alive to the lions.
The incident highlights the plight of many of the country’s farm workers, who are still being treated appallingly a decade after the end of apartheid.
In one particularly brutal incident, a white farmer in eastern South Africa was sentenced to 25 years in 2001 for killing a black employee by tying a rope around his neck and dragging him along a gravel road behind a pick-up.
“We see this case as an illustration of the kind of problematic relationship that there are on farms,” said Marc Wegerif of the Nkuzi Development Association, an organisation seeking to protect the rights of farm workers
“There is clearly a massive power imbalance between farm owners and farm workers.”
The Congress of South African Trade Unions, the country’s largest labour federation said: “While the incident is exceptionally brutal, the trade unions know that the abuse of workers 10 years after the democratic breakthrough is still rife.”
The South African Human Rights Commission said in 2003 it had “received many complaints on human rights violations that occur in our farming communities”.