Children believed to be aged 15 were found during a joint operation by the Hawks and Department of Labour when they conducted a raid at a Chinese factory in Johannesburg.
The department’s provincial chief inspector, advocate Michael Msiza, said on top of the trafficking of illegal immigrants, who were subjected to forced labour, numerous laws were broken.
It found the company, Beautiful City (Pty) Ltd, "was employing 150 employees and 149 of them were illegal or undocumented foreigners", Msiza said in a statement.
The blitz inspection, according to Msiza, followed a tip-off in August.
The informant alleged that the Chinese employers were engaged in the trafficking of Malawian nationals.
Information obtained by the department found the migrant workers were locked in the factory 24 hours a day.
"The employer was violating labour legislation pertaining to the National Minimum Wage, Occupational Health and Safety Act and the Basic Conditions of Employment Act," said Msiza.
He also revealed the employer was found to be in violation of South Africa's immigration legislation, by-laws, health regulations, and engaging in child labour.
The employer has been arrested by the Hawks and all the employees found on the premises were recorded and taken to a place of safety.
As a result, the company has been issued with a compliance notice for failing to pay the national minimum wage.
Underpayment for the 78 employees found on the premises was estimated to be around R6.3m and the employer has to pay them within 14 days of receipt of notice.
The business was also issued with a prohibition notice by department inspectors, which means that no one would be allowed to gain entry into the business.
"Such barbaric acts have no place in our democratic state that upholds and promotes freedom, equality and human dignity. There is no human dignity in locking in employees and violating their rights in employment including a right to earn a minimum wage and to be covered regarding social security," Msiza said.