Police in Mpumalanga say a demonstration by striking Hlanganani security personnel at Kusile power station has ended.
Hlanganani Protection Services employees went on strike over the alleged non-payment of salaries on Friday morning, blocking the way into the plant.
Just before 14:00 Brigadier Leonard Hlathi said police had intervened and the employees had dispersed without incident.
"The strike is about security guards who say they were not paid by the company. Police went and engaged with them and reached an understanding. The road was then cleared and the situation is now stable," said Hlathi.
Hlathi would not say whether or not the gathering was approved by authorities. He called it an attempt at a "barricade".
Eskom confirmed to Fin24 on Friday morning that several employees of one of its contractors were attempting to prevent construction at the coal-fired power plant.
Spokesperson Dikatso Mothae said she could not say how many employees were involved. She did, however, say construction workers had already made their way onto the site by the time the demonstrations began, so construction was not halted.
Hlanganani, meanwhile, told Fin24 it would not comment on the strike.
Kusile and Medupi, the third and fourth largest coal power plants in the world, were originally due to come online in 2014 and 2012, which would have given the country an extra 9600MW of power, enough to avoid blackouts.
But both are presently still under construction with a growing price tag.
In early April Eskom chairperson Jabu Mabuza said previously that Medupi and Kusile would need R18bn each to complete.