Muller's dairy plant in Somerset has been impacted by an outbreak of Covid-19 among its 300-strong workforce.
The dairy firm said 47 of its workers had tested positive for coronavirus at its milk factory, which is located near Bridgwater.
One worker at the North Petherton-based site had died after contracting the virus, the company added.
Around a third of its workforce are now self-isolating and production has since been reduced.
Workers at the plant are classed as key workers by the government because they are involved in food production.
A spokesman for Müller Milk & Ingredients stressed that the factory's fresh milk processing was 'highly automated' and there were 'no risks' to its products.
"As we have done throughout the pandemic, we are placing the safety of our employees first and following best practice as set down by the Health and Safety Executive," he added.
"Standard measures in place include the use of facemasks, distancing, enhanced deep cleaning and hygiene, underpinned by a programme of e-learning, information and audits to ensure compliance and awareness of the measures."
Somerset County Council, Public Health England and Muller are working together to conduct further testing.