National police commissioner General Khehla Sitole welcomed the arrest of five suspects and the recovery of an estimated R4m.
It is believed the suspects and the recovered money can be linked to inside jobs at cash-in-transit companies.
Spokesperson Lieutenant Colonel Brenda Muridili said one of those arrested was a security guard who had disappeared with a large amount of money.
The guard collected the money from a bank on April 30. The company later opened a case at the Hillbrow police station.
The case was then transferred to the Provincial Investigating Unit (PIU) for investigation, leading to the arrest of the guard on May 17 in Doornfontein, Johannesburg.
Zenzele Nicho Khanyile's case has been postponed to May 29 in the Hillbrow Magistrate's Court.
The close collaboration between the police and the private sector resulted in the recovery of more than R200 000 in Nkandla, KwaZulu-Natal, and about R500 000 in American dollars.
Fidelity employees implicated
On Wednesday, News24 revealed that a stash of money, of more than R1m, which was found at a house in Ekurhuleni on Monday, was stolen by two Fidelity employees.
Fidelity CEO Wahl Bartmann told News24 that the two employees had been caught when they only handed in some of the bags at the depot.
Bartmann said the money that was recovered was estimated to be about R1.6m.
Muridili said on Thursday that the two men, Clement Matjoji and Mbangiseni Rapholo, had allegedly collected money from various clients on May 7.
She said the company then opened a case of theft, involving an estimated at R4.6m, at the Germiston police station. This case was also transferred to PIU for investigation.
"The detectives worked in collaboration with the Ekurhuleni Metropolitan Police Department (EMPD), taking an integrated approach in the fight against cash related crimes."
Motjoji and Rapholo were subsequently arrested. They are expected back in the Germiston Magistrate's Court on May 23.
Cash buried in backyard
EMPD spokesperson Chief Clifford Shongwe said at the time that a reliable source had led them to the house on Monday evening, where they found a couple with "a lot of money in their possession" that made them suspicious.
"They then led us to a hole which they dug to hide a trunk full of undisclosed cash."
According to Muridili the house belonged to the brother of Rapholo.
Two people were arrested. They are expected to appear in the Germiston Magistrate's Court on Thursday.
Over the past few weeks there have been a number of cash-in-transit heists.
Last week, there was a dramatic robbery on two cash vans in Boksburg and another attack on a van at Southdale Mall, just outside the Johannesburg CBD, over the weekend.
There was another heist on a cash van at Jabulani Mall in Soweto, as well one in Limpopo. On Wednesday night, there was an attempted heist on the N3 south.