Premier Ebrahim Rasool says the National Intelligence Agency (NIA) and the police are investigating written death threats allegedly made by the Chinese triad mafia against him and Community Safety MEC Leonard Ramatlakane.
Rasool said letters had been received warning that if they continued with a campaign to arrest highflyers, they would be "eliminated".
Yet one such suspected high-flyer and his syndicate had since been arrested.
"These threats are being taken seriously," Rasool said in an interview at his official residence, Leeuwenhof.
"The police and NIA are investigating and police commissioner (Mzwandile) Petros confirmed that when any member of government or the police is threatened, they will investigate and take the necessary steps to ensure the fight against crime is successful. This is a standard police procedure and not an order from me.
"The original threat came in a meeting held between the triads and the South African gang the Junior Mafias. It was reported to us that they would eliminate me and minister Ramatlakane if we were to continue our campaign."
Rasool said top international, national and local gang leaders operating in major South African cities had met to discuss ways of dealing with the provincial campaign, endorsed by President Thabo Mbeki, to arrest and prosecute the country's top 200 "highflyer" criminals.
At this meeting they apparently resolved to stop infighting and target politicians, said Rasool.
"They are desperate to make sure that drugs and perlemoen smuggling become bigger businesses. But we have promised to tackle this problem because drugs and gangsterism are turning our children into killers and drug dealers," he said.
"We bust the major syndicate, so that means the order out on us has been activated. We are not going to be intimidated or feel threatened."
According to Rasool, the syndicates include South Africans and Tanzanians.