Former Cosatu general secretary Zwelinzima Vavi and EFF leader Julius Malema are plotting to overthr.
The men, aged between 26 and 37, were arrested on Saturday in Musina, the border town between South Africa and Zimbabwe.
Police spokesman Brigadier Hangwani Mulaudzi confirmed that they had arrested five Ethiopians and an Indian and in the process rescued 47 Ethiopian men who he said were destined to be sold off as slaves in different parts of the province.
He said the group apparently arrived in Musina some time last week and were smuggled out of the refugee centre under mysterious circumstances. They were taken to different "safe" houses in Makhado and Thohoyandou.
"The syndicate's illegal activity was uncovered on Saturday after a relative opened a kidnapping case," Mulaudzi said yesterday.
He said the complainant had told the police that the group was smuggled into the country and that five of his family members - out of the group of 47 - were allegedly being held against their will.
The relative further claimed that he was ordered to pay R10000 to get them released, Mulaudzi said.
"We then organised a sting operation through which the complainant was in contact with the syndicate members which culminated in a meeting at a well-known car dealership in Louis Trichardt.
"The complainant was in possession of the R10000 which led to the arrest of two of the suspects and the rescue of the five victims," he said.
Mulaudzi said after questioning the suspects, they were directed to four other syndicate members who were in Golgotha, Thohoyandou.
"After apprehending them, the suspects led us to a house next to the University of Venda where [a further] 42 victims were rescued," he said, adding that the victims were found in good health.
They are being kept at a safe place pending the outcome of the investigation.
Mulaudzi said the six suspects, all of whom had businesses in Thohoyandou, were being investigated for additional links to similar activities in other countries. They will appear in the Musina Magistrate's Court today on charges of kidnapping.
Meanwhile, provincial police commissioner Simon Mpembe yesterday lauded the police actions and reiterated the province's resolve to fight any form of criminality. Mpembe said organisers of these ventures were taking advantage of vulnerable people and putting their lives at risk.