Five suspects allegedly linked to the R200m OR Tambo Airport heist were arrested over the weekend.
One of the suspects arrested at luxurious Centurion estate, was in possession of a Lamborghini and a large amount of cash.
Detectives swooped on the luxury home of the gang's alleged boss Sunday after he uploaded pictures to social media of himself and friends posing with his new £320,000 wheels.
Sign up to our daily newsletter for your chance to win. The foreign currency was due to be deposited on a flight to London.
However, police have been unable to confirm this. Other news agencies have cited lower figures.
The kingpin is suspected of being the brains behind a slick raid at South Africa's main worldwide airport which saw an armed gang dressed as police officers seize £15million in cash as it was loaded on a plane to London. A group of robbers disguised as police stole millions of rand in foreign currency in a recent heist at the airport.
The source said police are expected to make further arrests.
According to information, the people in the photo are policeman and not suspects as reported.
Police arrested more suspects at several locations in Gauteng on Saturday, bringing the number of people being held for the robbery to seven. Phahlane said that investigators had not ruled out the possibility that the robbery was an "inside job" orchestrated with the help of police officers.
Police spokesperson Sally de Beer says: "We note regrettably that a police officer was among the five arrested at the weekend".
But it's emerged that the vehicle, pictured in viral social media posts about the arrests, was not bought with the proceeds of the robbery.