The Northwestern Health Unit (NWHU) this week said a COVID-19 outbreak had been declared at the mine, with a workplace outbreak defined as two or more cases who likely became infected at the workplace.
New Gold said three employees had tested positive, while seven had tested "non-negative" with the in-house PCR device and were awaiting confirmation from the NWHU.
It said all affected individuals had been isolated and were no longer on site.
"The company has a comprehensive COVID-19 response plan in place and the health and safety of our workforce and our communities remain our number one concern," president and CEO Renaud Adams said yesterday.
New Gold said it would provide updates "as appropriate".
Ontario has a stay-at-home order in place for six weeks to stop the rapid growth in cases.
Rainy River had two COVID-19 cases in the March quarter and there were four during the period at the company's New Afton mine in British Columbia.
New Gold has said it was focus on optimising its operational and cost performance at Rainy River, which was set to transition to generating sustainable free cash flow, having completed a turnaround in 2020.
The Rainy River 2021 production guidance outlined in February of 275,000-295,000oz gold-equivalent assumed operations would continue without any significant COVID-19-related interruptions.
New Afton, where a deadly mudslide occurred in February, was expected to produce 165,000-195,000oz Au-eq this year.
New Gold shares (TSX: NGD) are trading near the middle of a one-year range, closing up more than 3% yesterday to C$2.28 to capitalise it at $1.5 billion (US$1.2 billion).