Sandra Moonsamy, the daughter of a multibillionaire logistics tycoon, who went missing in May, was found "bound in chains" when police swooped on her alleged kidnappers on Thursday evening.
Moonsamy has been missing for more than 160 days.
The Hawks confirmed that Moonsamy was found alive during an intelligence-driven operation in Emalahleni (Witbank) Mpumalanga.
Police confirmed that two men were arrested in Gauteng, and two others in Emalahlani.
Hawks spokesperson Brigadier Hangwani Mulaudzi said Moonsamy was found conscious but in a "bad state" in a house in Mpumalanga, and not Mamelodi as they were originally informed.
He said she was recovering in hospital.
Moonsamy, a Westville mother of two and a financial director of Crossmoor Transport, was allegedly taken from her black Range Rover after allegedly being forced off the road by three vehicles on the M13 offramp on Stapleton Road in Pinetown on the evening of May 30.
Moonsamy is one of two daughters of transport logistics moguls Lutchmee and Poonsamy Naicker.
Mulaudzi said that shortly after her witnapping, the family received calls demanding a R140m ransom.
"An intensive investigation by the Hawks task team ultimately traced and located four suspects, two were arrested in Johannesburg. Further investigations by the team led to the arrest of two additional suspects in Emalahleni.
"[Moonsamy] was found bound in chains at a house in Emalahleni and was subsequently rescued by an integrated team of the Hawks assisted by Crime Intelligence, Gauteng Provincial Organised Crime members and Ekurhuleni Metro Police.
"Three luxury vehicles worth m and a firearm have since been seized for further investigation," said Mulaudzi.
He added that the four suspects – aged between 30 and 34 – were expected to appear in the Durban magistrate’s court on Monday to face a charge of kidnapping. Other related charges could be added at a later stage.
A source close to the investigation said the family hired a private investigator to help after ransom requests were sent to them.
The only early development in the case came with the arrest of a 35-year-old Nigerian, Jerry Ogbuwany Gike, in July. The man was found in possession of one of her cellphones.
Gike has appeared in court on several occasions. On August 13 he was granted bail of R5,000. The case has since been postponed to December 2.