Theron said this was not an outbreak at the mine, as the cases were mainly from workers returning to the mine who had tested positive before reporting for work.
"We are in the process of retesting and verifying the positive results. If confirmed, it means they were infected at home in theie local community."
Theron said of the 19 cases, two of the people had recently returned from the Eastern Cape, while 17 cases were of people who lived locally, suggesting the prevalence of Covid-19 among local communities is far higher than the company's initial estimates.
Theron said given that Implats had also identified positive cases among some private health-care providers working in the community, the company also tested all its medical staff working at the mine clinic.
NUM North East regional secretary Phillip Mankge said the union expected all mining companies to adhere to strict health and safety measures in fighting the virus.