Emfuleni Municipality in the Vaal has beefed up security around its town manager by assigning bodyguards to her after she received death threats through her cellphone.
It is believed the threats to Mmapusetso Bakane-Tuoane were linked to a corruption investigation against municipal officials in various departments.
Bakane-Tuoane, a former North West government director-general, has helped the council uncover several corrupt activities through operation "Fiela Ngwanana" (sweep clean, girl), which, according to the municipality, is aimed at fighting corruption.
The latest incident involved five officials who were suspended after it was established that they were involved in corrupt practices.
More than 20 cases are currently being investigated.
The municipality has been plagued by widespread theft, corruption, fraud and money laundering for some time.
Paseka Rakosa, Emfuleni communications manager, told Sowetan there was information that certain people were unhappy that Bakane-Tuoane was trying to rid the council of corruption.
"Though most of the threats the manager has received were made via cellphone, there have been more serious warnings. She reported that she discovered something unusual at her home last month and a police unit was made aware. We do not want to take any chances," said Rakosa.
Vanderbijlpark police spokesman Constable Mandla Zwane said he was not aware of the death threats against the manager.