Johannesburg - A Sanral employee who was arrested for alleged "terrorist acts" in Centurion was tracked down through a call made from his cellphone, the Hawks said on Thursday.
"We linked him via his cellphone which was used to make a call," said Captain Paul Ramaloko.
"We are not sure if he was operating the cellphone alone."
The 28-year-old Soweto man was accused of involvement in two white powder scares and a bomb scare at the SA National Roads Agency Limited headquarters in the past two weeks.
"We are convinced that we netted the mastermind behind all three incidents," said Ramaloko.
The bomb scare took place on Sunday. The building was evacuated and a sweep carried out. No bomb was found.
The premises was also evacuated on Tuesday and Friday after a suspicious powder, initially feared to be anthrax, was found.
Electronic Toll Collection (ETC) later reported that the substance was harmless.
The man, who worked in Sanral's call centre, was expected to appear in the Pretoria Magistrate's Court on Friday on charges relating to acts of terrorism.
"The man was arrested at Sanral's Central Operations Centre in Centurion while on duty. During his arrest a cellphone, suspected of having been an instrument used to commit the offence, was seized," Ramaloko said.
ETC on Thursday said it could not comment as the case was sub judice. - Sapa