The officers were arrested in Gauteng and the other three people, one a notorious member of the 26s gang, in the Western Cape, Lt-Gen Solomon Makgale said.
Wednesday’s arrests were part of “Operation Combat”, created to respond to ongoing gang violence in the Western Cape.
“Investigations by the team uncovered a racket involving the fraudulent issuing of firearm licences to applicants,” Makgale said.
“This included the process from the initial application to the firearm training facility involved, to the police stations where the applications are lodged and the head office where the applications are approved.”
Officers raided the SA Police Service central firearm registry office in Pretoria and seized documents and electronic equipment.
In Cape Town, officers confiscated firearms and ammunition.
The six face charges including illegal possession of firearms, fraud, corruption, and racketeering.
Makgale said national police commissioner Riah Phiyega commended the team for the arrests and said more could be expected as the operation entered its second phase.