Fifteen members of the now disbanded Durban Organised Crime Unit have been arrested, the Hawks said on Wednesday.
Spokesman McIntosh Polela said the arrests were part of a joint operation by the Hawks and the Independent Police Investigative Directorate (IPID).
Three members were arrested in Gauteng - two in Hammanskraal, north of Pretoria, and one on the West Rand. The rest were arrested in various locations around Durban.
Polela said a total of 20 members of the unit would be arrested.
He said the unit's commanding officer Maj-Gen Johan Booysen, who was also the KwaZulu-Natal boss of the Hawks, was not one of the 20.
Those arrested were taken to the SA Police Service air wing at the old Durban International Airport.
None of them resisted arrest, Polela said.
IPID spokesman Moses Dlamini confirmed the operation.
The 20 face charges ranging from murder and the unlawful possession of ammunition to theft and assault.
The unit was shut down in February amid allegations that an alleged death squad operated in the Cato Manor crime unit.
Most of its members have since been incorporated into the Hawks.
Booysen was issued with a notice of suspension in March, but it was later set aside.
He faced allegations of negligence or failing to act in connection with the alleged death squad.