Harmony Gold spokesperson Sihle Maake said yesterday that the theft took place after security personnel outside the mine entrance were ambushed and tied up.
“The intruders proceeded to the plant and gained access to the smelter house by breaching security measures,” said Maake.
“Fortunately, all plant personnel are safe and accounted for, so there were no fatalities during the incident.
"As the investigation is still sensitive and ongoing, we cannot confirm the monetary value of the stolen stock at this stage."
But experts said the robbery would not affect the group’s total production.
Seleho Tsatsi, an investment analyst at Anchor Capital, said yesterday that the robbery was an unfortunate incident.
“From a financial perspective, it's not especially material to Harmony Gold's earnings. To illustrate, Harmony sold 34 150kg of gold for the fiscal year 2017.
"So this theft amounts to 0.04percent of the fiscal year 2017’s gold sales,” Tsatsi said.
Harmony Gold share price closed 0.78percent weaker on the JSE.
“Given that number, it seems more likely that the Harmony Gold share price decline today is more tied to the wider stock market being down rather than investors focusing on this incident.
"Having said that, these types of incidents are unfortunately always concerning,” Tsatsi said.
Kalgold is an isolated open pit mine that is surrounded by farmland.
It is on the Kraaipan Greenstone Belt, 55km south-west of Mahikeng, along the N18 in North West.
The closest community to the site is to be found about 15km south of the mine.
This is not the first time Kalgold mine has been targeted.
In 2015, six men aged between 26 and 54 were arrested for conspiracy to commit robbery.
At the time, it was reported that the suspects, who were driving a Ford Courier, found their way to the mine gate, which was manned by security guards.
It was also alleged that an- other vehicle, a Mercedes-Benz Iveco, arrived at the gate immediately after the Ford Courier.
The suspects then allegedly shot at the guards, who returned fire and the attackers fled the scene.
Two of them were arrested immediately.
Harmony also reported the killing of a manager last August.
Simphiwe Kubheka, the regional general manager of the Tshepong operation near Odendaalsrus in the Free State, was shot dead on his way home.
It was alleged at the time that Kubheka was attacked and murdered by illegal gold miners, who are also known as zama-zamas.
Organised labour said the killing spoke to how unemployment, poverty, greed and weak leadership worked together to push South Africa ever deeper into anarchy.
Harmony reported last month that two employees had died at its Joel Mine in the Free State after a seismic event that happened at the mine.
- BUSINESS REPORT