A third contractor at Eskom was on Wednesday positively linked to an act of sabotage at the beleaguered power utility.
Eskom says he was arrested on Tuesday at its Camden power station in Mpumalanga.
The comes after last week's incident when two contractor truck drivers were arrested while in possession of stolen coal.
In the latest incident, the perpetrator is believed to have intentionally removed the bearing oil drain plug from the bearing causing the oil burners to trip repeatedly.
Eskom spokesperson Sikhonathi Mantshantsha said this act of sabotage was to ensure that his employer is awarded additional maintenance and repair jobs at the power station.
He said Camden Unit 4 subsequently tripped after losing all the mills during the incident which occurred on Thursday, 10 November, at approximately 16:54.
Intensive internal investigations led to the culprit being identified and questioned about the incident.
"It is disheartening to find that some of our contractors are unscrupulous, have malicious intent and are willing to plunge the country into further loadshedding at a time when the electricity grid is highly constrained," said Advocate Karen Pillay, General Manager for Security at Eskom.
"We have always suspected that some of our maintenance contractors and employees are behind these acts of sabotage. We shall continuously work with the law enforcement agencies to bring these insiders to book and ensure that justice is meted out, but most importantly that those with similar tendencies across Eskom are arrested and removed from the organisation," added Pillay.
