The incident, which happened at the weekend, left Prasa red-faced and investigating how the two men tricked the guards.
The two suspects allegedly drove the train all the way to Umgababa, and when it stopped they jumped out and fled into a nearby forest while being pursued by security guards.
According to an employee, who asked not to be named, the train only stopped when it lost momentum in an uphill area.
Another Prasa employee, working on the railway line at the time of the incident, expressed her shock.
In a social media post, the employee said she believed those behind the train theft were whoonga addicts.
“I thought I had seen it all in my career, but no. While we were busy working on other trains, two drug addicts stole one train that was staged and drove it from eMkhomazi all the way to Umgababa - an entire train.
“Just think about it, the complication of starting it, releasing the brakes, accumulating vacuum before it can actually depart,” said the source.
Prasa spokesperson Zama Nomnganga said they were unwilling to reveal too many details about the incident because the investigation was “highly sensitive”.
Nomnganga said the train was running at the time when the two allegedly decided to take it.
“That was a high-risk activity, as anything could have happened to them. It was irresponsible of them. This is not a PlayStation,” he said.
Nomnganga said the incident could have had tragic consequences. “They could have had a head-on collision and they could have killed people, or they could have derailed the train,” he said.
He said the incident had raised serious concerns about security.
“Our train drivers wear blue and white and are easy to identify. We will look at insisting everyone wears uniforms with name tags so they are easy to identify,” he said.
Zama Sabela, of the SA Transport and Allied Workers Union, described the incident as “peculiar”.
“We urge authorities to speed up the investigation so the perpetrators can be brought to book.”
Cosmas Doncabe, the deputy secretary of the United National Transport Union, said it was the first time he had ever heard of such an incident.
“As far as I know, driving a train is not a simple task. It takes about six months of training in different courses to be competent,” he said.