An employee and a medic at Elon Musk’s SpaceX have tested positive for coronavirus, causing the company to put at least 12 of its workers in quarantine.

Employees were told on Monday afternoon that two people working at the company's facility in Hawthorne, near Los Angeles had the virus, according to a company email seen by The Telegraph.

Mr Musk has repeatedly sought to downplay the severity of the pandemic, declining to close Tesla and SpaceX facilities even as the state of California became subject to an order requiring residents to stay at home other than for essential journeys.

One employee had been diagnosed after travelling abroad, and the company said the risk to others was "very low" and "no greater than going to the grocery store", because the person had spent just one day on site, last Monday.

Staff who have come into close contact with the employee have been asked to quarantine themselves for 14 days, and the company said it was doing a "video review" of their movements to see if any others could have been affected.

A second individual who worked at the on-site medical centre came into "close contact" with 12 employees in the three days before they began to feel unwell. These people have also now been placed in 14-day quarantine.