Two voters in Barberton, Mpumalanga, say they managed to cast more than one vote on Wednesday at different voting stations.
One voter, who requested to remain anonymous, told News24 that she was registered to vote at the Barberton Town Hall.
She however, decided to rather vote at the St Johns Church polling station. She was not asked to complete the section 20A form, which is protocol if a voter does not vote at their registered polling station.
She then decided to see if she could get a form at Barberton High School, which also did not have the forms.
The woman then went to her registered voting station, where she made her mark. After voting, she went back to the St Johns polling station, and to Barberton High School, where she went ahead and again voted, apparently spoiling her ballot papers.
Ettiene Mare, editor of online digital news agency Suburb.News in the Lowveld, also decided to test the system.
Mare was registered to vote in Nelspruit.
He visited the St Johns polling station in Barberton, where he managed to cast his vote, using the Section 20A form.
At the Barberton Town Hall, Mare voted for a second time. This time he did not fill in the form.
He recorded the whole incident on video.
"I also spoilt the second ballot paper by making crosses at the top 10 political parties to make sure it could not be counted," he said.
He published the video online, which went viral on social media.
Bosman Grobler of the DA said the incident was of great concern.
"The whole integrity of the election could be questioned. We reported the matter to the IEC."
Mpumalanga IEC spokesperson Sibusiso Nkosi said he did not want to comment yet, as the police were investigating the matter.