South Africans working in the country's vineyards and fruit farms are being exposed to pesticides and unsafe working conditions, a report by Human Rights Watch said.
The report, released Tuesday, said workers were also blocked from forming labour unions, and were among the worst paid in the country.
Workers lead "dismal, dangerous lives," the report found, while on-site housing was unfit for habitation. It also cited lack of access to toilets or drinking water for workersn while on the job.
The majority of the abuses reportedly take place in the Western Cape Province, which is home to six of South Africa's nine wine growing regions.
Farm workers contribute millions to the economy of South Africa, which the Guardian reported is the world's seventh largest producer of wine.
The report said that farm workers benefit very little despite their pivotal role in the success of the country's fruit, wine, and tourism industries - “in large part because they are subject to exploitative conditions and human rights abuses without sufficient protection of their rights."
Human Rights Watch's Africa director, Daniel Bekele, said:
The wealth and wellbeing these workers produce should not be rooted in human misery. The government and the industries and farmers themselves need to do a lot more to protect people who live and work on farms.
Human Rights Watch has urged South Africa's government to do more to enforce strict labour laws.
But the BBC spoke to the head of Wines of South Africa, Sue Birch, who said the study's claims were unbalanced and upsetting, and would be investigated.
The respondents were identified by trade unions and NGOs who have a vested interest in producing the very worst examples.
The report was based on more than 260 interviews with farmworkers, farm owners, civil society members, industry representatives, government officials, lawyers and union officials.