An operations centre in Centurion for the South African National Roads Agency Limited (Sanral) had to be evacuated on Friday and two people quarantined after another anthrax scare, police said.
"The Sanral offices were evacuated after an anthrax scare and we have specialists on the scene to see if the white powder found was anthrax," Lieutenant Colonel Katlego Mogale said.
"Two people have been quarantined and taken to hospital." Mogale said more details were not immediately available.
Sanral spokesperson Vusi Mona could not immediately be reached for comment.
On Tuesday, Sanral said the Gauteng highway tolling system was disrupted when Sanral's operations centre in Pretoria had to be evacuated.
Mona could not say how the system was disrupted.
"Our priority is to ensure the safety of the people who work at the central operations centre," he said at the time.
The Tshwane hazardous material unit was called to the centre on Monday afternoon after a "suspicious envelope containing a white substance" was found on the premises.
This resulted in the shutdown of electricity and the evacuation of the building.
Mona said Sanral took the matter seriously and condemned this type of action because it was "tantamount to sabotage and borders on a very serious crime".
On Wednesday, Sanral said the substance found in the envelope was not dangerous.
Thirty-seven people were decontaminated and hospitalised as a precaution.
All of them had been discharged by Wednesday morning.
At the time, chief executive Nazir Alli said the evacuation did not compromise the toll collection process and toll gantries remained operational. –Sapa