The police declined to comment about the evacuation of the SA National Roads Agency Limited’s (Sanral) operations centre in Pretoria on Tuesday.
“We not do not any comment on this,” said Brigadier Neville Malila.
The evacuation of Sanral’s office caused the Gauteng highway tolling system to be disrupted on Tuesday, the company said.
Spokesman Vusi 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 in a statement.
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.
“We take this matter very seriously and condemn this type of action in the strongest possible terms,” said Mona.
“It is tantamount to sabotage and borders on a very serious crime,” he said.